Christine Ohuruogu and Nicola Sanders both put in superb performances to clinch World Championship gold and silver in the 400m final in Osaka.
Ohuruogu dug deep in the final couple of strides to get the win
The British duo finished fast to overhaul Jamaica's Novlene Williams in the final strides.
Earlier Jo Pavey booked her place in the 5,000m final after finishing fourth in her semi-final.
American Jeremy Wariner looked comfortable as he reached the 400m final after winning his heat.
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1440: Another day has come to an end and what a day for British duo Christine Ohuruogu and Nicola Sanders!
Thursday is another day in Osaka so what have we got to look forward to? There's Tyson Gay v Usain Bolt in the 200m final and the women's 200m reaches the semi-final stage with Veronica Campbell aiming for a sprint double.
It's a quiet day for the Britons with Tasha Danvers-Smith in the 400m hurdles final, Andy Turner in the 110m semi-finals while Michael Rimmer aims to advance in the 800m.
1434: God Save The Queen rings around the Nagai Stadium as Christine Ohuruogu is presented with her gold medal. The 23-year-old battles to keep her composure and eventually the tears start to flow.
1428: 100m winner Tyson Gay says he is a bit tired after his victory in the shorter sprint but he wins his semi-final in 20.00 seconds although he was made work hard by Jamaica's Marvin Anderson who sets a new pb. Ireland's Paul Hession is sixth.
1420: Semi-final time in the men's 200m. First honours go to the impressive Usain Bolt of Jamaica in 20.03, just ahead of American Wallace Spearmon. Bolt runs the bend very well but eases off to the line and is looking very very strong.
"I just wanted to make it to the final and take it from there," Bolt told BBC Sport.
1418: Baddeley ran a poor tactical race and really left himself down. He could have definitely finished in the top 6.Isabre on 606
1412: Andy Baddeley, who finished ninth in the 1500m spoke to BBC Sport afterwards: "It was very hard out there and I'm disappointed. I didn't think I ran too badly but the pace fluctuated a lot. I think I can get a medal at the Olympics but I'd like to have got a medal today."
1409: It's a dramatic sprint finish and it's American Bernard Lagat, who formerly represented Kenya who takes the win. Lagat was nicely placed going into the home straight and the second-fastest ever over the distance claimed gold. Bahrain's Rashid Ramzi was second, just ahead of Kenya's Shedrack Kibet Korir.
1405: Deep breath - next final is on track. It's the 1500m with Andy Baddeley hoping to be inspired by the 400m success.
1400: Ohuruogu and Sanders have shown that we can produce the athletes and they can perform at the highest level.
captainpenguin on 606
The new 400m world champion told BBC Sport: "Winning a world title will probably sink in later because to me, I've just won a race. It was very tough for me. I'm proud because I got up every single day and trained hard with the World Championships in mind."
1352: What drama! Novlene Williams of the Bahamas makes the better start but both Christine Ohuruogu and Nicola Sanders keep in touch and with Williams struggling in the home straight, the British pair pounce with Ohuruogu winning gold in 49.61 and Sanders winning silver in 49.65, both personal bests.
1349: Donald Thomas, the former basketball player turned athlete wins the high jump for the Bahamas. Second is Russian Yaroslav Rybakov and bronze goes to Kryiakos Ioannou of Cyprus.
1347: Nicola Sanders and Christine Ohuruogu are on the track for the women's 400m final going through their final preparations.
1341: Tim Benjamin trails in sixth in his 400m semi-final. The Briton went off quickly but was soon caught and struggled after that. The race was won by American LaShawn Merritt with Frenchman Leslie Djhone second. It means Americans have won all three heats. What price a clean sweep in the final?
Benjamin later told BBC Sport: "I woke up this morning with sore throat and had a fever. I'm just having bad luck."
1335: Jeremy Wariner makes it look easy in the second 400m semi-final, winning in 44.34 and that's with him practically jogging across the finish line. Second is Chris Brown of the Bahamas but Ireland's David Gillick is down in sixth.
Afterwards Wariner told BBC Sport: "I did what Michael Johnson asked me to do - I ran a good race and was able to cruise in. My main concern is defending my title and the way I ran today I believe I can."
1331: Martyn Bernard's gamble fails to play off as he misses again at 2.35m and goes out. With the departure of Stefan Holm, there are only three athletes left in the competition.
1326: The first of the three semi-final in the 400m goes to American Angelo Taylor in 44.45 seconds with Sweden's Johan Wissman setting a new national record in second in 44.56 to advance.
1325: Donald Thomas of the Bahamas puts in a phenomenal first-time jump at 2.35m to go into the lead in the high jump. Britain's Martyn Bernard misses with his first attempt and has just one more effort to stay in the competition.
Former World champion and BBC analyst Michael Johnson on the 400m semi-finals:
Jeremy (Wariner) is in the zone where he is capable of putting in some big time. It's going to be tough for Tim Benjamin who is in there with some fast people.
1317: Newly crowned 100m Michelle Perry is delighted with her display as she tells BBC Sport: "I didn't know I had won and then Ginny (team-mate Ginny Powell) told me I had won and I looked at the scorebord. I'm happy to have won amd I will take a few days off to relax and see Japan."
"What a competitve race. It's great to see the favourite win but also to see her pushed all the way to the line. Michelle Perry has great fluency which gives her the title. It was a fantastic race."
BBC analyst Colin Jackson
1313: Martyn Bernard is continuing to baffle one and all with his tactics in the high jump. He misses his first attempt at 2.33m, having had just one clearance at 2.21, and is passing on his next two attempts to move to 2.35.
1307: It's medal time again. And in those 12 or so seconds defending champion Michelle Perry dug deepest to win gold. Canada's Perdita Felicien, the former world champion, wins silver and bronze goes to Jamaica's Delloreen Ennis-London.
1305: Next track final is the women's 100m hurdles which will be over in the blink of an eye.
1300: Tom Parsons can't make it three in a row and he misses at 2.30m for the third time to finish in 10th place overall. After passing on his last two heights, Martyn Bernard will now go for a lifetime best at 2.33.
1252: Joy for the veteran German Franka Dietzsch as she wins the women's discus thanks to her first-round effort of 66.61m. Silver goes to Russia's Darya Pishchalnikova with Yarelis Barrios winning bronze.
1240: Jo Pavey advances to the 5,000m final after finishing fourth in her semi-final. She moved into contention with three laps to go but was forced to work hard on the home straight.
She told BBC Sport afterwards: "It was tough. I'm very pleased to qualify although I had never tried to do a 5k after a 10k.
"My calves are a bit sore and my legs were dead. I came into the race tired so I don't know how ready I will be for the final. I'm going to be mentally positive and you can't turn down a chance to compete at a World Champs."
1235: For the second height in a row, high jumper Tom Parsons clears at the third attempt. This time it is 2.26m. Martyn Bernard is also still in contention after passing on that height.
1232: The women's triple jump qualification has just ended. No British interest here but the best jump comes from Greece's Hrysopiyi Devetzi, the Athens Olympics silver medalist, who hops, skips and jumps her way to 15.09m
1230: After 1000m Pavey is lying towards the back of the field but this is looking like being a patient run from her.
1225 Jo Pavey is on the starting line for her 5,000m heat - here's hoping she can recover from her 10,000m exertions.
1221: Turkey's Ethiopian-born Elvan Abeylegesse wins the opening women's 5,000m semi-final, leading home a group of five automatic qualifiers, who finish well clear of the rest of the field.
1211: Nervous moments for high jump duo Tom Parsons and Martyn Barnard who both manage to clear 2.21m at their third attempts.
1207: From the women's sprints to the women's long-distance. The 5,000 heats are under way minus the defending champion and 10,000m winner Tirunesh Dibaba and steeplechase winner Yekaterina Voklkova. Jo Pavey, an agonising fourth over 10,000m goes in the second semi and we'll let you know how she gets on.
1203: German Franka Dietzsch is setting the pace in the women's discus final - her ninth World final. The 39-year-old defending champion leads with 66.61m and followed that up with 66.48 in the second round, laying down a challenge to her rivals.
1200: And Jamaica's Aleen Bailey follows team-mate Campbell by winning the fourth of the quarter-finals but former European champion Muriel Hurtis-Houairi from France is out.
"The stadium in Osaka is the emptiest we seen it so far during these championships. It's a shame because there is a great night of athletics in prospect."
BBC commentator Steve Cram
1152: The 100m champion Veronica Campbell wins the third of the women's 200m quarter-finals to keep alive her hopes of a sprint double.
1145: The first of Britain's two high jump final contenders in action is Tom Parsons and he clears 2.16m with his first attempt. Martyn Bernard passes at the height. But it's early days there at the moment.
1143: A disappointed Joice Maduaka departs the 200m after only finishing seventh in her quarter-final, which is won by Allyson Felix. Maduaka said: "I did what I was told to do and picked my points on the track. I fought all the way down and I tried the best I could."
1140: World 400m champion Sanya Richards, who missed out on selection for that event, wins the first quarter-final in 22.31 seconds, a season's best. She told BBC Sport: "I felt really good, I've been working on my speed." Richards lost a $20,000 necklace in the morning session - happily owner and necklace have now been reunited.
1135: The first track action of the evening session is about to get under way - the quarter-finals of the women's 200m with Sanya Richards, Allyson Felix and Veronica Campbell all in action, along with Briton Joice Maduaka.
1128: Andy Turner will be in action again on Thursday in the semi-finals. He told BBC Sport: "I was nervous going into this race. My target was to win the heat but there is more to come. The start was apprehensive but I felt relaxed out there. I've got a PB under my belt but I hopefully I can go quicker again."
1125: So, what have you missed so far today? Bad news for Goldie Sayers (javelin), and long jump duo Chris Tomlinson and Greg Rutherford who missed out on their finals. But good news for Andy Turner, who set a new personal best to advance in the 110m hurdles.
1110: We're at the midway point of the competition and there's a change in this seat with Sarah enjoying a well-earned rest while I take over.
Wednesday sees a real chance for Britain to add to its medal tally. Nicola Sanders and Christine Ohuruogu go in the 400m final. Andy Baddeley goes in the 1500m final while Tom Parsons and Martyn Bernard go in the high jump.
Medals will also be decided in the women's discus and the 100m hurdles where Sweden's Susanna Kallur carries European hopes against the likes of American duo Michelle Perry, the reigning champion, and LoLo Jones and the 2003 champion Perdita Felicien of Canada.