British and Irish Lions coach Warren Gatland rings in the changes for Saturday's second Test against the Wallabies, beefing up his pack for a "do or die" battle against the Australians.
He was forced to switch two of his front five because of injuries, but has added Wales flanker Dan Lydiate to the back row in place of Tom Croft as one of five changes to the team that won the first Test 23-21 a week ago.
And he has taken experienced scrum half Mike Phillips completely out of the second Test to save him for the third in Sydney because of a nagging knee injury.
Ben Youngs replaces Phillips and Tommy Bowe returns on the right wing after making a three-week recovery from a broken hand that required surgery after the win over Queensland Reds. He takes over from Brisbane try scorer Alex Cuthbert.
"This is a do or die match for Australia and it's going to be a real battle out there. We've decided to add a little bit more physicality to our side up front," said Gatland.
"Dan Lydiate brings that and then we have the explosiveness of Tom Croft and Sean O'Brien to come off the bench. We are really happy with the quality we have on the bench.
"Tommy Bowe is obviously quality and he brings a lot of experience. He has been a fantastic player for both Ulster and Ireland and he has made a fantastic recovery from injury.
"Mike Phillips was fit and available, but he has had problems with his knee. It has been sore and he hasn't been able to take a full part in training. The decision was to rest him for this week and he is potentially an important component for next week.
The Lions are chasing a win at the Etihad Stadium this weekend that would earn them a first Test series victory since 1997. They went 1-0 up in the last series in Australia 12 years ago, but then lost the last two Tests.
"One or two changes were forced on us, and we've got a couple of players coming back from injury, but it just shows how strong the squad is and that we have a huge amount of competition," added Gatland.
"I don't know who made that thing up about not changing a winning side - it is about picking the best team to do a job for us. We can win this series by winning on Saturday and that's where our whole focus needs to be.
"The last thing we want to think about is being one-all and having to play another game in Sydney. Everything for us is about Saturday night."
England's Mako Vunipola and Geoff Parling are promoted from the replacements to take the places of Corbisiero in the front row and Paul O'Connell in the second row.
"We said after the first Test that we had improvement in us and we are confident that this is the case," said Gatland.
British and Irish Lions (15-1) - Leigh Halfpenny; Tommy Bowe, Brian O'Driscoll, Jonathan Davies, George North; Jonathan Sexton, Ben Youngs; Jamie Heaslip, Sam Warburton, Dan Lydiate; Geoff Parling, Alun Wyn Jones; Adam Jones, Tom Youngs, Makovina Vunipola. Replacements: Richard Hibbard, Ryan Grant, Dan Cole, Tom Croft, Sean O'Brien, Conor Murray, Owen Farrell, Alex Cuthbert.
The Wallabies made two enforced changes with Kurtley Beale and Joe Tomane coming into a recast backline for the must-win second Test.
Beale, who missed a winning penalty attempt in the final minutes of the Wallabies’ 23-21 first Test loss, replaces the injured Berrick Barnes at fullback while Tomane takes over from winger Digby Ioane.
Coach Robbie Deans retained James O'Connor at fly-half despite his mixed reviews in last week's Brisbane Test and following pictures published in a British newspaper showing him out at 4:00 am on Wednesday after watching his Super Rugby team, the Melbourne Rebels, fall 35-0 to the Lions.
Beale was reportedly with him, although both players denied they were drinking and a Wallabies spokesman told reporters neither broke team rules.
Australia (15-1) - Kurtley Beale, Israel Folau, Adam Ashley-Cooper, Christian Leali'ifano, Joe Tomane, James O'Connor, Will Genia, Wycliff Palu, Michael Hooper, Ben Mowen, James Horwill, Kane Douglas, Ben Alexander, Stephen Moore, Benn Robinson. Replacements: Saia Fainga'a, James Slipper, Sekope Kepu, Rob Simmons, Liam Gill, Nick Phipps, Rob Horne, Jesse Mogg