You could barely get a cigarette paper between the two teams seven days ago and with so much at stake on Saturday night it is likely to be the same again. Pick a winner if you dare.
Let's just put into perspective what is at stake under the Etihad Stadium roof. Firstly, the Qantas Wallabies are the current holders of the Tom Richards Trophy and they are hell bent on holding onto the fancy piece of glassware. If this tour has been 12 years in the making, then it is going to be a long, hard 12 years for the current Wallabies if they don't hold onto the prize.
It is do or die for James Horwill and his players - just as it was 12 years ago for the Australian team led by another Queensland second row, John Eales. Having been brushed aside by the Lions in Brisbane in the first Test in 2001, and found themselves trailing at half-time in Melbourne, Eales' team conjured up three great halves of rugby from there on in to win the series. Will history repeat itself?
On the other hand, this is the best prepared Lions team in history and has arguably the greatest strength in depth and experience of any team sent overseas. They arrived in Australia with one mission, to end the 16 year wait for a Test series triumph. So far, so good!
The skin of the teeth win at the Suncorp Stadium gave the Lions the early momentum in the series, but the loss of Paul O'Connell and Alex Corbisiero through injury could be costly. The Wallabies have had to reshuffle their back line, but we all know the game is going to be won up front and if the Lions don't get the same stranglehold on possession, and function as well at the set pieces as they did for most of the game, it is going to be a long night.
Warren Gatland's reaction to winning last weekend has surprised a few people. Five changes, two of them enforced through injuries, flies in the face of the old adage that claims you should never change a winning team. What Gatland wants is the best team on the field for the specific challenge and by bringing in Tommy Bowe's experience and class behind the scrum, and Dan Lydiate's extra power in the back row, he clearly has a plan in mind.
As well he might given Wallaby coach Robbie Deans' statement this week. When asked what sort of game it is going to be he quickly replied "it's going to be a ripper!" Scene set, cards on the table - it's going to be all guns blazing!
So, what does Melbourne represent for the Lions? Just how big is this game in the grand scheme of things for this 125-year-old romantic rugby entity?
"We're desperate to win the series," explained Gatland. "We know how tough it is to put a squad together in such a short period of time and play away from home against one of the top three countries in the world. It;s a tough ask to do that every four years.
"But we are desperate for the Lions to be successful. I think world rugby wants the Lions to be successful. Success is about having a close, tough Test match series, and this is what we've got at the moment.
"We had it four years ago and we are well aware that a winning Lions series will help all those things going forward. If you don't, then the pressure comes on and the criticism of it comes on us. There is no hiding from the fact that it is important for the Lions to win."
The two teams will have learned a lot about each other from last weekend's initial sparring session, What did we learn?
That the Australian scrum is not to be taken lightly, that Will Genia is a class act and that you simply can't give Israel Folau an inch.
That the Lions line-out and driving maul are top notch, that George North is a potent attacking weapon and that Leigh Halfpenny is deadly with his boot.
That the breakdown is the most important battle ground, reading the referee is vital and that you have to keep on playing right up to the 80th minute.
What will it all come down to in the end, and will we go to a third Test decider for the third successive series in Australia? The bookies would make you think so, but if the Lions can keep their discipline, cut down on the penalties they gave away last week and put a stranglehold on the Wallaby pack then victory can be theirs - both on the night and in the series.
Wallaby skipper James Horwill said his team were ready to play the second Test from the second they came off the pitch in Brisbane. Injury problems, late nights out for Kurtley Beale and James O'Connor and an IRB 'U turn' on Horwill's citing decision this week have done nothing to change the captain's opinion on that.
As for the Lions, and Brian O'Driscoll in particular, it is a day of destiny. O'Driscoll was in Melbourne 12 years ago when the series slipped out of the grasp of the 2001 tourists. He doesn't want to see another golden chance lost!