McLaren’s Jenson Button topped the times in FP2 for Sunday’s Turkish Grand Prix as world championship leader Sebastian Vettel was forced to sit out the entirety of the session following his shunt this morning.

The circuit was unrecognisable from the damp and misty morning run, with the rain having stopped and the sun quickly drying the Istanbul venue. And, in stark contrast to the first session, the drivers were keen to get on to the circuit as quickly as possible, with a glut of F1 cars filling the track.

Button first went quickest 20 minutes in, heading team-mate Lewis Hamilton in a McLaren one-two. They were then trumped by Mercedes pairing Nico Rosberg and Michael Schumacher, the seven-time champ heading his team-mate on the hour mark. Three-time Turkish victor Felipe Massa was quickest at halfway point, before being toppled by Vitaly Petrov and then Rosberg.

Button then retook P1 with half an hour remaining and remained there as the teams switched their attention to race setups. Jenson ended up ahead of his fellow Mercedes-powered cars of Rosberg, Hamilton and Schumacher, suggested the German powerplants are hitting the rights notes this weekend.

The quickest Red Bull was fifth fastest Mark Webber, though we’d be surprised if the Aussie isn’t duking it out for pole tomorrow.

The same is probably true of Sebastian Vettel, but having missed half of FP1 and all of the afternoon run the German is fighting something of an uphill battle. We know both he and the car have the pace, but his start to the weekend has been far from ideal, with the 23-year-old yet to complete a dry lap in Istanbul. There’s an interesting story developing there.

Elsewhere there were plenty of problems for Williams newboy Pastor Maldonado today, the Venezuelan suffering several spins despite finally competing at a track he has raced extensively at. Meanwhile FP1 pacesetter Fernando Alonso missed a large chunk of the session with hydraulics woes, then suffered an inocuous looking spin when he did hit the track. As he returned to the pits his car died on him, and the two-time champion had to be pushed back to his garage. Turkey was a nightmare for the Spaniard last season and 2011 doesn’t like being much better. However Ferrari team-mate Massa fared better, ending the session sixth.

There were also strong displays from rookies Paul di Resta and Sergio Perez, who ended the day eighth and ninth fastest respectively.

Third practice takes place tomorrow at 11am local time before the all-important qualifying session gets going at 2pm (12pm UK). With Vettel’s problematic Friday there’s certainly an added dimension to the story as the German goes in seek of his fourth successive pole position of 2011 – could Turkey finally see another driver on P1 when the flag falls on qualifying.