At the end of the second practice session before the season-opening Australian Grand Prix on Sunday, it was the surprise duo of Jenson Button and Lewis Hamilton, both McLaren drivers, who led the way with the fastest times at the Albert Park.

Disappointing in pre-season sessions with a worrying lack of pace, McLaren team Principal Martin Whitmarsh had confirmed during the week that in order to step up their pace, the team would resort to some radical upgrades. The upgrades involved a new exhaust system, abandoning their 'octopus' for one similar to that used by Ferrari and Red Bull. With their performance, it would seem the upgrades did have the desired effect.

In the first session of the day, both Button and Hamilton set out with some long runs on soft tyres. Convinced with what they saw, they pushed hard on the second session to clock times which were the fastest of the day with Jenson Button coming through in one minute 25.852 secs, 0.132 secs ahead of Lewis Hamilton. Fernando Alonso of Ferrari finished third fastest - 0.147 off Button and World Champion Sebastian Vettel came fourth after coming in 0.160 off Button.

Button was pleased after coming through untroubled, saying, Reliability something we've not had all winter, so to have a car that runs for as many laps as we want it to is very satisfying. It also means we can get stuck into our set-up work and improve the car. I don't think there's much to be gained from looking at today's times though, so I'm not going to get too carried away.

The new exhaust has definitely brought performance to the car - it feels much better, makes the handling more 'complete'. When you have downforce at the rear, you can also add it at the front, and then you put temperature in the tyres - there's so much that comes with downforce.

However, Hamilton exercised joy with caution, saying, The grip level today felt like a big step forward. We don't know what fuel loads the others are running, but our car feels like a big improvement from where we were just a few weeks ago.

Mercedes' Michael Schumacher, who impressed in the final pre-season practice session, came in behind fifth placed Mark Webber while Ferrari's Felipe Massa came in at seventh. Renault, touted to pose some challenge for the favorites this season after their performance in Melbourne disappointed with both Vitaly Petrov and Nick Heidfeld outside the top ten.

As any long-time F1 enthusiast can vouch for, practice sessions rarely point to the end result of the race and Red Bull and Ferrari may as well push forward in the qualifiers on Saturday and the race on Sunday.

At the end of the session, the FIA confirmed with a statement that a minute's silence would be held on the grid out of respect for all the victims of the recent natural disasters in Japan, Australia and New Zealand.