Button pips Rosberg in second practice

The majority of the session was a battle between the McLarens and the Mercedes, with Button and team-mate Lewis Hamilton the early pacesetters, before first Rosberg then Michael Schumacher hit the front towards the end of the first half-hour.

Three-time Istanbul winner Felipe Massa then briefly got Ferrari to the head of the pack with a 1m27.959s lap, 0.3s quicker than Schumacher.

He only stayed in front for three minutes before Rosberg reclaimed the top spot, which he held until just after the hour mark, when Button moved comfortably clear of the pack with a 1m26.456s on the softer tyres.

Rosberg later closed to within 0.065s, but that lap was sufficiently to keep Button in first place to the end.

Hamilton and Schumacher were third and fourth, the latter's car escaping damage in a late spin at Turn 11 which appeared to be triggered when Schumacher was surprised by a Force India coming past him.

Red Bull kept a relatively low profile, with Mark Webber staying in the midfield and doing longer runs for much of the session before eventually doing a time that would stand for fifth, ahead of Massa. Vettel was not able to run at all, the team soon realising that repairing the session one damage in time would be impossible. That means the points leader will go into the rest of the weekend with no dry mileage at all.

Renault's Vitaly Petrov, another man who topped the timing screens fleetingly in the early running, was seventh, while the Force Indias of Paul di Resta and Adrian Sutil sandwiched Sergio Perez's Sauber in the final three top 10 positions.

It was a tough session for Fernando Alonso. A hydraulic problem kept him in the Ferrari garage for a spell, and he later spun at Turn 6 before taking 11th.

The only driver whose mistake took him as far as the barriers was Pastor Maldonado. The Williams driver ran slightly wide on the way out of Turn 8, found a damp patch and slid into the barrier.

At the tail of the field, the Virgins languished some way off even Hispania's pace until the closing stages when both Jerome D'Ambrosio and Timo Glock edged a few tenths ahead of Narain Karthikeyan.

Pos  Driver                Team                    Time               Laps
 1.  Jenson Button         McLaren-Mercedes        1m26.456s            26
 2.  Nico Rosberg          Mercedes                1m26.521s  +	0.065	29
 3.  Lewis Hamilton        McLaren-Mercedes        1m27.033s  +	0.577	31
 4.  Michael Schumacher    Mercedes                1m27.063s  +	0.607	21
 5.  Mark Webber           Red Bull-Renault        1m27.149s  +	0.693	31
 6.  Felipe Massa          Ferrari                 1m27.340s  +	0.884	37
 7.  Vitaly Petrov         Renault                 1m27.517s  +	1.061	37
 8.  Paul di Resta         Force India-Mercedes    1m27.725s  +	1.269	37
 9.  Sergio Perez          Sauber-Ferrari          1m27.844s  +	1.388	32
10.  Adrian Sutil          Force India-Mercedes    1m28.052s  +	1.596	37
11.  Fernando Alonso       Ferrari                 1m28.069s  +	1.613	27
12.  Sebastien Buemi       Toro Rosso-Ferrari      1m28.153s  +	1.697	36
13.  Nick Heidfeld         Renault                 1m28.475s  +	2.019	35
14.  Jaime Alguersuari     Toro Rosso-Ferrari      1m28.765s  +	2.309	32
15.  Pastor Maldonado      Williams-Cosworth       1m28.828s  +	2.372	19
16.  Rubens Barrichello    Williams-Cosworth       1m28.946s  +	2.490	20
17.  Jarno Trulli          Lotus-Renault           1m29.409s  +	2.953	39
18.  Kamui Kobayashi       Sauber-Ferrari          1m29.637s  +	3.181	27
19.  Heikki Kovalainen     Lotus-Renault           1m30.281s  +	3.825	37
20.  Jerome D'Ambrosio     Virgin-Cosworth         1m31.035s  +	4.579	28
21.  Timo Glock            Virgin-Cosworth         1m31.221s  +	4.765	22
22.  Narain Karthikeyan    HRT-Cosworth            1m31.320s  +	4.864	29
23.  Tonio Liuzzi          HRT-Cosworth            1m31.989s  +	5.533	30

All Timing Unofficial