American Tyson Gay stayed on track for a double success at the World Championships in Osaka by clocking the fastest time in the 200m semi-finals.
Gay has looked in impressive form in Osaka so far
The 100m champion coasted home in 20.00 seconds with Jamaica's Usain Bolt winning the other semi in 20.03.
American trio Jeremy Wariner, Angelo Taylor and LaShawn Merritt triumphed in the three 400m semi-finals.
Britain's Jo Pavey reached the 5,000m final after finishing fourth in her semi-final.
Pavey, who finished fourth in the 10,000m, dug deep to clock a season's best time of 15 minutes 11.83 seconds.
"It felt harder that it should, but obviously I would normally do the 5K fresh and my calves were actually hurting," said Pavey.
"The impact was painful. When I did the 10K they didn't hurt at all, so going into it with damaged legs is not ideal."
There was also a good performance from Andy Turner who set a personal best of 13.27secs to advance in the 110m hurdles.
But there was plenty of disappointment for the British team as Goldie Sayers, Chris Tomlinson and Greg Rutherford failed to reach their finals.
Javelin thrower Sayers, ranked fourth in the world, struggled to reach 57.23m - almost eight metres down on her season's best.
"My legs were so dead and I couldn't attack the line, I feel really tired and I did not have it in my legs at all," she said.
In the long jump, British record holder Tomlinson only managed 7.89 metres to finish 16th, 10cm short of the qualifying distance.
Both Wariner and Taylor looked impressive as they reached the 400m final while Merritt had to work hard for his win in a race where Tim Benjamin finished down the field in sixth.
Joice Maduka struggled to live with the pace set by defending world champion Allyson Felix and failed to secure a place in Thursday's 200m semi-final.
American 400m specialist Sanya Richards clocked an impressive 22.31 seconds in the first of the quarter-finals to go through as the fastest qualifier.
Donald Thomas claimed a suprise high jump gold for the Bahamas
Elsewhere, American Michelle Perry defended her 100m hurdles world title, leaning past Canada's Perdita Felicien on the line.
Perry clocked 12.46 seconds with Felicien, the 2003 champion, in 12.49 and Jamaica's Delloreen Ennis-London third in 12.50. Sweden's European champion Susanna Kallur was fourth.
Bernard Lagat landed another gold for America in the 1500m with a late surge to hold off Rashid Ramzi of Bahrain and Shedrack Kibet Korir of Kenya with Britain's Andy Baddeley in ninth.
Defending champion Franka Dietzsch won her third world discus crown at the age of 39 in her ninth world championship with a best of 66.61 metres.
The veteran German, who also won the title in 1999, landed the winning throw with her first effort to hold off the challenge of European champion Darya Pishchalnikova of Russia who threw 65.78m.
Newcomer Donald Thomas emerged victorious in the men's high jump in only his second season of competition.
Thomas, who just missed a medal at last year's Commonwealth Games in Melbourne, cleared 2.35m metres at his first attempt.
He took gold ahead of Russia's 2005 silver medallist Yaroslav Rybakov and Kyriakos Ioannou of Cyprus with none of the trio managing 2.37.
Tom Parsons finished 10th with 2.26 while Martyn Bernard, who passed on a number of heights, was 14th with his best clearance coming at 2.21.