The 24-year-old Welshman will lead the Lions out at a packed Docklands Stadium against a wounded Wallabies side desperate to thwart their bid to capture a first series win since 1997.
Warburton, who began the tour under an injury cloud and even had his place under threat from rival flankers in the squad, knows full well that nothing can be taken for granted and pledged to treat the test as if it were his last.
"This week, really, it's quite strange to wake up every day knowing that it's this time in five days that you could be test series winners, then it's four days, then three. Now it's two days and the game couldn't come quick enough," he told reporters on Thursday.
"I think it will be biggest game (of my career) because the potential achievement will be something no-one else has achieved for the last four tours.
"Normally you're pretty nervous in a week going into a big game for your club or country but this one it's just complete excitement and it couldn't come quick enough."
The Lions will play in front of around 50,000 fans in Melbourne, where the closed roof will amplify a frenetic atmosphere and keep the turf dry and primed for running rugby.
Warburton will no doubt be mindful of history, however, and know that the Lions' 2001 series began to unravel at the same venue.
Having thrashed the Wallabies in the opener at the Gabba, the Lions led 11-3 in the first half before Joe Roff scored two tries after the break to spark Australia to a rousing 35-14 victory.
Warburton was also among the Wales side left heartbroken at Docklands last year, when replacement back Mike Harris calmly slotted a penalty kick after the siren to lift Australia to a 25-23 win and seal the three-match series.
"The talk around the players is that we do need to finish it this weekend and there's been no complacency thinking that we've got a week off because we've got an opportunity next week, because momentum would completely swing," Warburton said.
"They'll bounce back. They were only a kick away from winning last week so they know they've got every chance of getting the test series back.
"Australians being Australians, they're probably optimistic. They're very good competitors. There's no way that they'll be down and out. I imagine they'll come out firing.
"Like Gats (coach Warren Gatland) said, it's all or nothing for them now, we've just got to expect a huge performance from them."