Mercedes’ Nico Rosberg set the fastest time of opening practice for the Belgian Grand Prix with the German also becoming the first driver to set a timed lap in a session using the Halo device, which underwent more testing.

As the session got underway at Spa-Francorchamps, four cars took to the circuit sporting the cockpit head protection device – Toro Rosso’s Carlos Sainz, Red Bull Racing’s Daniel Ricciardo, Force India’s Nico Hulkenberg and Rosberg.

All except Rosberg used the device for a single installation lap, but as times began to be registered, Rosberg moved to the top of the order with a lap of 1:49.481 with the Halo attached. It was the first time the device has completed a timed lap in a grand prix session.

After a brief period in the Mercedes garage Rosberg then returned to the track with the Halo still attached but with supersoft tyres onboard. He quickly set a new benchmark of 1:48.348.

The time was good enough for Rosberg to head the timesheet for the remainder of the session. Team-mate and championship leader Lewis Hamilton finished in second place, seven tenths off Rosberg.

Hamilton also used a new turbocharger and MGU-H in the session, power unit alterations that will earn him a 15-place grid penalty this weekend as the Briton has exceeded the maximum for the season.

Kimi Raikkonen was third for Ferrari. The Finn set his best time on soft tyres, as did Force India’s Sergio Perez who finished in fourth place, almost a full second behind Rosberg.

While Raikkonen got to just within eight tenths of a second off P1, Sebastian Vettel ended the 90 minutes in fifth place, 1.5s adrift of Rosberg and over six tenths behind his Ferrari team-mate.

After removing the Halo, Daniel Ricciardo worked through a low-key session, finishing sixth. The Australian just over a tenth behind Vettel and eight hundredths of a second clear of team-mate Max Verstappen who finished seventh. Force India’s Nico Hulkenberg was eighth ahead of the Williams of Valtteri Bottas, with Haas' Esteban Gutierrez completing the top 10.

Nineteen-year-old French driver Esteban Ocon, who is set to make his Formula One race debut with Manor this weekend, finished in 16th position, a second ahead of team-mate Pascal Wehrlein.

It was a frustrating start to the weekend for Fernando Alonso, however. Honda have brought a comprehensively updated power unit to this race but problems with the powerplant mean that Alonso completed just three laps in FP1. The Spaniard failed to set a time and finished in 22^nd place.

2016 Belgian Grand Prix – Free Practice 1
1 Nico Rosberg Mercedes 1:48.348 27
2 Lewis Hamilton Mercedes 1:49.078 25
3 Kimi Raikkonen Ferrari 1:49.147 24
4 Sergio Perez Force India 1:49.274 23
5 Sebastian Vettel Ferrari 1:49.768 19
6 Daniel Ricciardo Red Bull Racing 1:49.782 24
7 Max Verstappen Red Bull Racing 1:49.865 24
8 Nico Hulkenberg Force India 1:50.088 21
9 Valtteri Bottas Williams 1:50.394 31
10 Esteban Gutierrez Haas 1:50.583 21
11 Romain Grosjean Haas 1:50.899 18
12 Felipe Massa Williams 1:51.122 28
13 Marcus Ericsson Sauber 1:51.125 16
14 Carlos Sainz Toro Rosso 1:51.424 17
15 Felipe Nasr Sauber 1:51.768 19
16 Esteban Ocon Manor 1:51.787 26
17 Daniil Kvyat Toro Rosso 1:52.308 19
18 Jenson Button McLaren 1:52.407 18
19 Pascal Wehrlein Manor 1:52.837 23
20 Kevin Magnussen Renault 1:53.053 20
21 Jolyon Palmer Renault 1:53.089 20
22 Fernando Alonso McLaren  3