All times GMT
80 mins: The final whistle goes to signal a famous victory for the Lions. It might be raining in Sydney but the Great Britain fans' spirits cannot be dampened.
78 mins: DROP GOAL: Australia 12-23 Great Britain
After missing his earlier kicks, Sean Long recovers and puts the seal on a superb display with a drop goal to continue the Lions celebrations.
76 mins: TRY Australia 12-22 Great Britain
Australia are awarded the scrum but Great Britain hold their possession superbly and Adrian Morley puts in a strong challenge on Lockyer. Somehow Sean Long gets to the ball and breaks away. With Australia stretched and James Roby in support, Great Britain sends the ball out wide and Gareth Raynor goes over to seal the win. Long misses the kick when it hits the upright.
73 mins: Darren Lockyer's dangerous-looking kick on the final tackle hits off Jamie Peacock, who looks suspiciously offside but Great Britain retain possession.
70 mins: Long has a chance to make amends but he misses a drop goal.
69 mins: Kirk Yeaman wins a crucial penalty 17 metres out and Great Britain have a glorious opportunity but Sean Long, under pressure, manages to misses it. Hopefully that won't come back to haunt Great Britain.
68 mins: Tense moments for Great Britain but Australia are the masters of coming from a losing position to win in the final five or 10 minutes.
66 mins: Great Britain seem to find an extra gear in defence and they are helped when Shaun Berrigan concedes a penalty with a knock-on.
64 mins: A mistake by Gareth Hock around 12 metres out on the first play after Gilmour's try puts the pressure back on his teammates and they need to defend well again.
62 mins: TRY Australia 12-18 Great Britain
From the repeat set of six, Leon Pryce finds Lee Gilmour on the third tackle. Gilmour times his run superbly on the angle to go over and score with Long kicking again.
60 mins: Sean Long is proving a key influence for the Lions and his low kick into the in-goal area has to be dealt with by the Australians.
57 mins: Ben Hornby and Karmichael Hunt both challenge for the ball in what looks like a try-scoring opportunity but Gareth Raynor somehow gets back to deny him but Hornby comes off worst and Great Britain breath another sigh of relief.
55 mins: A moment of madness by Jamie Peacock who offloads and hands possession back to Australia
54 mins: A crucial passage of possession for Great Britain as they get to within 10 metres of the Australia line in a bid to stay in the game but the Kangaroos defence hold firm.
52 mins: TRY Australia 12-12 Great Britain
The inevitable happens with an Australian attack, the ball is fed out wide from Shaun Berrigan to Greg Inglis who races down the wing and passes inside to captain Darren Lockyer who scores his 30th international try and adds the extras.
50 mins: A let-off for the Lions as Willie Mason gets involved again and knocks on with the try-line at his mercy. Great Britain are struggling a little at the moment.
48 mins: The Australians are rattled and start to pile on the pressure and force another set of possessions. The Lions need to defend well.
45 mins: A moment of inspiration from Darren Lockyer who breaks downfield and sends a kick ahead but Jamie Lyon is not quick enough to latch onto it.
42 mins: TRY Australia 6-12 Great Britain
A quick play the ball by Great Britain and the Australian defence cannot cope with captain Jamie Peacock who goes over the line. There is an anxious 90 seconds as the try is analysed by the video referee but eventually there is the green light. It is Peacock's first try in four years and the Australian crowd are stunned. Long has another successful kick.
41 mins: Sean Long, who has a bandage around his head after Willie Mason's intervention, is tackled high by Nathan Hindmarsh.
1004:Darren Lockyer begins the second half for Australia. This is going to be a fascinating 40 minutes.
40 mins: HALF-TIME: Australia 6-6 Great Britain
39 mins: Lee Gilmour has to be alert to send Karmichael Hunt's kick over the end line but Australia are unable to do anything with their repeat possession and the half-time hooter sounds with the sides level.
36 mins TRY Australia 6-6 Great Britain
A magnificent move by Sean Long who sends a dummy and breaks through the Australia challenge to pass to St Helens teammate Paul Wellens who goes over for a try. Long the provider adds the extra two points.
35 mins: Jon Wilkin comes on to make his Test debut. He could be the spark that Great Britain need.
34 mins: Australia are looking confident and with half time approaching, Great Britain should be on their guard to avoid conceding another try.
31 mins: And worse for Great Britain with winger Brian Carney forced off the field with a hamstring injury. Having stayed clear of injuries for most of the season with Newcastle, this is a cruel blow. Lee Gilmour comes on to replace him.
29 mins TRY Australia 6-0 Great Britain
Disaster for Great Britain. Sean Long's pass is intercepted by Ben Hornby close to their own line and the ball is fed out through Luke O'Donnell to Greg Inglis and nobody can stop him as he races downfield to score. It is similar to last week's Brent Webb effort for New Zealand and Darren Lockyer adds the extras.
27 mins: A lovely ball by Kirk Yeaman to Keith Senior who skips through a couple of tackles to make some more metres. A Sean Long kick has to be diverted out for a goal line drop out.
25 mins: Here comes James Roby who will be hoping for another good display after his impressive debut last week. Maybe his arrival can make a difference.
23 mins: A lovely burst through by Leon Pryce helps the Great Britain cause but Kirk Yeaman struggles with an offload and knocks on. The conditions are not particularly kind after some rain.
21 mins: A careless mistake as a pass to Sean O'Loughlin is forward and Australia get possession on halfway. But a mistake by Brent Tate gives the ball straight back to the Lions.
20 mins: A double blow for Australia with Petero Civoniceva and Mark Gasnier both off the field getting treatment for injuries but the home side are starting to look a bit more dangerous.
17 mins: Australia get close to the Great Britain line for the first time but Gareth Hock comes to the rescue with a crucial tackle on Willie Mason who knocks-on about 10 metres out.
15 mins: Adrian Morley comes on to replace Stuart Fielden. He is booed by the Australian supporters - this could be interesting.
13 mins: Great Britain have had more possession but need to make it count.
11 mins: Oh dear, Willie Mason strikes again - this time it is a very late challenge on Sean Long's head which takes him out. Long is bloodied above the right eye. Mason is put on report and Great Britain captain Jamie Peacock is furious. Mason is lucky to be still on the field.
10 mins: Nathan Hindmarsh concedes another penalty - Australia's fourth and the Lions can build again from halfway.
8 mins: Things have calmed down after the Willie Mason incident but Great Britain are looking strong.
5 mins:Great Britain make moves towards the Australia line through Leon Pryce but there is a knock-on in the build-up.
4 mins: Stuart Fielden is flattened off the ball by Willie Mason and a dust-up ensues but the Australian is only penalised with a penalty but should more severe action have been taken by referee Ashley Klein?
2 mins: Great Britain's first set of possession is solid as well.
1 min: Australia's opening possession sees them reach the halfway line but Ben Hornby's kick is grabbed easily by Brian Carney.
0906: The anthems over, Sean Long's kick begins the encounter.
0901: Both teams make their way onto the pitch for the national anthems.
0853: The players are going through their final warm-ups, keen to make up for last weekend's defeat to New Zealand.
0830: The weather could favour Britain this morning as it has been unusually cold and grey during the day in Sydney.
Great Britain half-back Danny McGuire has been ruled out of Saturday's Tri-Nations clash against Australia with a thigh injury.
Leon Pryce will now switch from wing to be paired with St Helens team-mate Sean Long for the Sydney clash.
Australia coach Ricky Stuart has made five changes after the 21-15 win over New Zealand on 21 October, with Willie Mason back from injury and starts for Ben Hornby, Shaun Berrigan, Brent Tate.
Former St Helens skipper Jamie Lyon also returns after a three-year absence because of his involvement in Super League.
Great Britain: Paul Wellens, Brian Carney, Keith Senior, Kirk Yeaman, Gareth Raynor, Leon Pryce, Sean Long, Stuart Fielden, Terry Newton, Jamie Peacock (captain), Gareth Ellis, Gareth Hock, Sean O'Loughlin.
Interchange: James Roby, Adrian Morley, Lee Gilmour, Jon Wilkin.
Australia: Karmichael Hunt, Brent Tate, Mark Gasnier, Jamie Lyon, Greg Inglis, Darren Lockyer (captain), Ben Hornby, Mark O'Meley, Shaun Berrigan, Petero Civoniceva, Willie Mason, Nathan Hindmarsh, Luke O'Donnell.
Interchange: Cameron Smith, Anthony Tupou, Brent Kite, Antonio Kaufusi.