SAKHIR, Bahrain — Mercedes drivers Lewis Hamilton and Nico Rosberg set the fastest times in Friday’s opening practice session for the Bahrain Grand Prix, making them once again the team to beat in Sunday’s race.

Hamilton set a best time of 1 minute, 37.502 seconds around the Bahrain International Circuit, a quarter of a second ahead of Rosberg. Fernando Alonso was third fastest in his Ferrari, half a second off Hamilton’s time.

Mercedes has won the opening two races of the Formula One season and could make it three straight in Bahrain, where the race will be held at night for the first time.

Four-time defending world champion Sebastian Vettel of Red Bull was 10th, 1.8 seconds off the pace, with the Renault-powered team a long way behind Mercedes in straight-line speed.

Force India driver Nico Hulkenberg was fourth fastest, while McLaren driver Jenson Button and Kevin Magnussen were fifth and seventh, respectively. Ferrari driver Kimi Raikkonen separated them.

Toro Rosso driver Daniil Kvyat, a 19-year-old rookie, was eighth quickest and Force India driver Sergio Perez was ninth.

The session was held in warm and sunny conditions in the afternoon, but the race will start at sunset in cooler ambient conditions. Friday’s second practice session is expected to be closer to race simulation.