World champion Sebastian Vettel set the pace in the second practice session at Spa on Friday ahead of Sunday’s Belgian Grand Prix.
The German suffered a puncture around 20 minutes before the end of the session but had done enough with a fastest lap of 1 minute 49.331 seconds, 0.059 seconds quicker than Red Bull team-mate Mark Webber.
Vettel, world champion of the past three seasons, had finished sixth in the morning session when Ferrari’s Fernando Alonso was quickest on a partly wet track.
In dry, sunny afternoon conditions, the Red Bull duo opened a gap of more than eight tenths of a second over third-fastest Romain Grosjean in a Lotus.
Ferrari’s Felipe Massa was fourth, ahead of Toro Rosso’s Jean-Eric Vergne Vergne, Grosjean’s team-mate Kimi Raikkonen and Alonso.
Lewis Hamilton, winner in Hungary in the last race before the summer break, was 12th, three places behind team-mate Nico Rosberg as Mercedes appeared to struggle.
McLaren’s Sergio Perez was eighth, while the Force Indias of Paul di Resta and Adrian Sutil were 10th and 11th respectively.
Alonso had posted 1:55.198 in the opening session, finishing ahead of Di Resta and Sutil, but it was team-mate Massa who had the greater pace in the afternoon.
Vettel leads the drivers’ championship on 172 points, with Raikkonen on 134 and Alonso on 133.
Rain was forecast both Saturday’s qualifying, which will determine grid positions, and Sunday’s race.