Mercedes team-mates Nico Rosberg and Lewis Hamilton topped the timesheets in first practice at Spa on Friday.
Mercedes' Nico Rosberg recovered from a sluggish start in first practice for the Belgian Grand Prix in Spa to finish quicker than team-mate and championship leader Lewis Hamilton.
The pair endured difficult outings at Hungary last time out, but, following the mid-season break, they went quickest with Rosberg clocking one minute 51.082 seconds in his 19 laps, while Hamilton managed five more, but was 0.242secs slower.
Red Bull's Daniel Ricciardo was third fastest in a session disrupted by Lotus drive Pastor Maldonado's crash, while Kimi Raikkonen, who agreed a new deal with Ferrari this week, was fourth with a quickest lap of 1:51.478.
Toro Rosso's Max Verstappen was among the quickest during the opening 45 minutes before Maldonado's spin interrupted practice.
The Venezuelan was given three penalties in Hungary and when he spun out on the exit of a turn and clipped tyres " damaging his wing and nose cone " a red flag brought all drivers back in.
Rosberg came out with a renewed optimism on the re-start " eager to make the most of his slow opening " and posted 1:51.200 to lead a front five of Hamilton, Ricciardo, Raikkonen and Sebastian Vettel going into the last 15 minutes.
Hamilton improved to challenge him with a 1:51.324s, but Rosberg proved too quick, setting the early pace ahead of second practice later in the day.
1. Nico Rosberg (Mercedes) 1:51.082
2. Lewis Hamilton (Mercedes) 1:51.324
3. Daniel Ricciardo (Red Bull) 1:51.373
4. Kimi Raikkonen (Ferrari) 1:51.478
5. Sebastian Vettel (Ferrari) 1:51.866
6. Daniil Kvyat (Red Bull) 1:51.960
7. Max Verstappen (Toro Rosso) 1:52.158
8. Carlos Sainz (Toro Rosso) 1:52.421
9. Sergio Perez (Force India) 1:52.423
10. Valtteri Bottas (Williams) 1:52.511