Jenson Button made the most of a small window of dry running to bolt on a set of Pirelli's supersoft tyre and claim the fastest time of day one at the Monaco Grand Prix.
With dark clouds and rain visible on the horizon, it was always likely that Friday's second free practice session would be wet at some point, but Button was one of only a handful of drivers who used the opening minutes to go for it on the faster of the two available tyre compounds. As a result, he blitzed Fernando Alonso's FP1 benchmark by half a second and, with the circuit remaining damp as the showers came and went, remained at the top of the pile for much of the 90-minute session.
Romain Grosjean repeated his FP1 effort by claiming second spot behind the McLaren, closing the gap to 0.392secs as running the soft compound slick remained possible, while Felipe Massa and Alonso pushed Ferrari into third and fourth, both also using the soft compound. Pastor Maldonado was the next best supersoft runner, in fifth place, with only Paul di Resta, Sergio Perez, Jean-Eric Vergne and Kamui Kobayashi also using the extreme rubber,
Once the rain arrived, the track fell silent as the teams though to sit out the worst of the precipitation. However, when, after 20 minutes of inaction, it failed to materialise into anything significant, the cars began to return to the circuit as rumours of a showery weekend caught the attention of the strategists.
Without a fully dry track to work with there was very little change in the order on the timesheets, and a heavier shower later in the afternoon ensured that there would be no movement at all late on. However, with grip levels varying, the session continued to provide a useful evaluation of Pirelli's two wet-weather tyres.
Of course, with tricky conditions come tricky moments and, while there was no repeat of Michael Schumacher's damaging brush with the barriers, several drivers had reason to thank their lucky stars as they skated down escape roads. The run-off at Mirabeau proved particularly popular as a damp patch at turn-in for the corner proved difficult to master, and both Williams drivers, plus Massa, Perez and Heikki Kovalainen were all caught out. Unfortunately for the Finn, who brought the morning session to an early conclusion with engine failure in the tunnel, he was the only one unable to resume after failing to find reverse gear on his Caterham.
Behind Maldonado, Nico Rosberg, Mark Webber, Kobayashi, Schumacher and Vettel rounded out the top ten, with Lewis Hamilton in eleventh after being thwarted in his efforts to follow team-mate Button's lead on supersofts. Perez, third fastest in the morning session, was down in 15th after likewise finding traffic on his run. Kimi Raikkonen, who lost the entire morning session to a steering set-up change, completed 25 laps after lunch, but was restricted to 19th on the timesheets.