Alonso fastest in wet/dry practice

Fernando Alonso emerged quickest for Ferrari as Spa's famous changeable conditions dictated proceedings in Formula 1's first session following its summer hiatus.

Early rain over the Ardennes circuit meant the first and final sectors were saturated, in contrast to the middle split where a dry line was rapidly established.

After the opening 15 minutes, in which McLaren's Jenson Button dominated, the mixed conditions effectively left the circuit too wet for slicks and too dry for intermediates, leading to a lull in activity.

The session finally sparked into life on the 45-minute mark as Mark Webber headed out on Pirelli's hard compound and immediately went fastest in sector two, even if his overall lap was some nine seconds off Button's early benchmark.

Webber's run, combined with several forecasts pointing to further showers in the closing minutes, inspired the entire the field to switch onto slicks and led to myriad changes at the top of the order. Sergio Perez was the first man to displace teammate Button with just over 30 minutes of the session to run, and on his next lap became the first man to dip below the 2m00s barrier.

Button reasserted himself immediately, only to be knocked off in turn by Nico Rosberg, Daniel Ricciardo and then Lewis Hamilton. Ferrari was still yet to post a single flying effort as the session moved into the final half hour, but when it did emerge Alonso instantly hit the front, moving clear with a 1m57.1s.

There was still time for that to be usurped, first by Perez and then by Force India's Paul di Resta, but Alonso's next lap finally settled matters, earning top spot by just two hundredths of a second.

Di Resta's effort was enough for second, while his teammate Adrian Sutil slipped into third, just ahead of Perez, Rosberg and Vettel.

Despite the conditions everyone managed to stay clear of the barriers, with incidents limited to a few trips down escape roads or run-off areas, particularly at La Source and the final chicane.