Sebastian Vettel returned to the top step of the podium as Mercedes failed to make the most of a front-row lockout at the Bahrain Grand Prix.

Valtteri Bottas claimed a maiden pole in qualifying on Saturday, ahead of team-mate Lewis Hamilton, but it was the Ferrari driver - winner of the season-opener in Australia before finishing second to Hamilton in China - who took the chequered flag in first place.

The German overtook Hamilton around the outside heading into turn one on the opening lap but found himself frustratingly held up behind Bottas, the Finn struggling to cope with pressure issues in his tyres.

As the chasing pack grew impatient, Vettel was first to show his hand when he pitted on lap 10.

A period under the safety car, following incidents that ended the races of Max Verstappen, Lance Stroll and Carlos Sainz, saw Ferrari make a significant return on their gamble.

Mercedes stacked their drivers in the pit lane but produced a pair of slow stops, sending Bottas back out behind the now leading Vettel, and Hamilton fourth behind Red Bull's Daniel Ricciardo.

Hamilton swiftly moved into third as Ricciardo struggled on his new soft tyres but Bottas' attempts to reclaim the lead were short-lived.

The Briton overtook his team-mate on lap 27, released into clean air with Bottas continuing to struggle on the super soft tyre before the former Williams man switched to softs on lap 31.

The timing of Vettel's second stop was to be a big call and, after pitting on lap 33, the four-time champion re-emerged behind Ferrari colleague Kimi Raikkonen and - crucially - ahead of Ricciardo.

Raikkonen was soon picked off and Hamilton's second stop - which also included a five-second penalty for earlier holding up Ricciardo in the pit lane - allowed Vettel to re-take the lead.

Hamilton's pace after that stop saw him chase down Bottas to take second, but the gap to Vettel proved too big to bridge, with the Ferrari man now seven points clear at the top of the drivers' standings.