Ferrari's Sebastian Vettel forged seven points clear at the top of the Formula One standings on Sunday after winning a Bahrain Grand Prix thriller that saw Lewis Hamilton penalised for underhand tactics.

Hamilton, who had started the floodlit race level on points with the German, took second place for Mercedes after staging a late chase following the five-second penalty for driving deliberately slowly into the pits.

Hamilton's Finnish team mate Valtteri Bottas was third after leading from his first pole position, struggling with his tyres and twice respecting team orders to allow the faster Briton through.

The victory was Vettel's second of the season after the four-times world champion won the opener in Australia. Hamilton, who won in China last weekend, crossed the finish line 6.6 seconds behind.

Vettel's 44th win lifted him to 68 points, with Hamilton second on 61 and the championship looking ever more likely to be an evenly matched battle between the two with Ferrari and Mercedes a cut above the rest.

"Yes guys, that's what I'm talking about," whooped the German, who was helped by a safety car after an aggressive early pitstop.

"It was a really great day. It was on the last half of the out lap when all the fireworks were going off that I was like 'I love what I do'," he said.

Hamilton's race, already compromised by Vettel passing him off the start for second place, unravelled further when he drove "unnecessarily slowly" as he came in for his first pit stop.

The move was a deliberate one to prevent Red Bull's Daniel Ricciardo getting the jump with a quick stop while Hamilton waited behind Bottas, already in the pits.

The Briton served the penalty at his second stop, frustration evident from his shaking helmet, before charging back and taking more than a second a lap out of Vettel's advantage.

The task of making up 20 seconds in 16 laps was ultimately too great a task.

BACK FOOT

"The pitlane was my fault and apologies to the team. I tried my hardest to catch up," said Hamilton, who thanked Bottas for his help.

Mercedes team boss Toto Wolff said the Finn's hopes of a first win had been hit even before the start when a problem with a generator on the grid left him with the wrong tyre pressures.

"From then on we were on the back foot," he said.

Bottas kept the lead for the opening laps, with Vettel close behind in a five-car train.

The safety car appeared on track after 18-year-old Canadian newcomer Lance Stroll, suffering his third retirement in three races, turned into Toro Rosso's Carlos Sainz as the Spaniard left the pits.

"I got hit from the side," the Williams rookie exclaimed.

Red Bull's Max Verstappen had already crashed out by then, blaming brake failure after he trekked across the gravel into the tyre barrier on lap 12.

"It was a great team effort today and I felt like we are quick. I tried to put Valtteri under pressure. But the early pit stop worked," said Vettel.

"Lewis obviously was a very big threat again towards the end... but the car was a dream today."

Ferrari's Kimi Raikkonen finished fourth with Australian Ricciardo fifth for Red Bull and Brazilian Felipe Massa sixth for Williams on the 75th birthday of team founder Frank Williams.

Mexican Sergio Perez finished seventh for Force India, his 13th successive points finish, with Frenchman Romain Grosjean eighth for U.S.-owned Haas.

Germany's Nico Hulkenberg was ninth for Renault, that team's first points of the year, and French rookie Esteban Ocon bagged the final point for Force India.

McLaren's nightmare continued with Belgian Stoffel Vandoorne failing to start and Fernando Alonso retiring on the final laps but classified 14th.

"I never raced with less power in my life," the Spaniard told his team.