Sebastian Vettel took his first win of the 2019 Formula One season at Sunday's Singapore Grand Prix, though his Ferrari teammate Charles Leclerc was aggrieved at losing the lead through what he termed an unfair strategy call.

With Leclerc leading the field away from his pole position, and Vettel sitting third behind the Mercedes of Lewis Hamilton, the German was the first Ferrari to pit for tyres on lap 20, taking advantage of his fresh rubber to emerge ahead of Leclerc when the Monegasque made his stop the following lap.

The early stages of the race were run at a slow pace, causing the pack to bunch closely together and giving team strategists a headache as they looked for a gap in the traffic for their drivers to emerge into post-pit stop.

Vettel noted after the race that his team had ordered him to pit at very short notice, suggesting that Ferrari thought the German had a better chance than Leclerc of emerging into clear air and lapping at speed.

Clearly irked at not having been given priority despite being the lead Ferrari, Leclerc radioed his team to complain that his treatment was unfair, especially when the call came through on lap 45 of 61 to concentrate on securing the team's 1-2 finish.

The Monegasque was more guarded in his immediate post-race interview, however, noting that the result was good for the team and pitting Vettel first was the only way that the team would have finished first and second.

Another driver to lose ground through a questionable strategy call was Hamilton, whose later pit stop dropped him from second to fourth behind the two Ferraris and the Red Bull of Max Verstappen, as he lost time on his older tyres relative to his rivals who had pitted earlier.

Behind the two Ferraris, Verstappen withstood a late charge from Hamilton on his fresher rubber to take the final podium place, with the Dutchman content at securing a top-three finish on a day when Ferrari had the measure of everyone.

Hamilton's teammate Valtteri Bottas finished fifth, after his own strategy was compromised when Mercedes ordered him to slow down to ensure that Hamilton would emerge from his stop ahead of the Finn.

With the lack of run-off area and the narrow, twisty confines of the Marina Bay Street Circuit giving drivers little margin for error, it was expected that the safety car would make at least one appearance during the race, and so it proved.

However, despite being deployed on no fewer than three occasions, the safety car did not significantly influence the course of the race, with none of the leading runners opting to use the periods of slower running to pit and switch onto a different strategy.

Verstappen's teammate Alex Albon finished sixth, ahead of the McLaren of Lando Norris, who had a better day after being unhappy at his qualifying performance on Saturday.

Pierre Gasly had an eventful run to eighth place in his Toro Rosso, having battled hard with Renault's Nico Hulkenberg, who finished ninth, with one-time race leader Antonio Giovinazzi rounding out the top ten in his Alfa Romeo.

Despite a disappointing afternoon, Hamilton remains top of the drivers' championship with 296 points, narrowly extending his lead over Bottas, who stays second on 231. Leclerc and Verstappen now jointly sit third with 200 points.

In the teams' standings, Mercedes stay top with 527, though the German outfit may privately be concerned that this is the first time since F1's turbo-hybrid era began in 2014 that they have gone three races without a victory. Ferrari's big haul of points moves them onto 394 points, while Red Bull sit third with 289.

The next round of the 2019 Formula One season is the Russian Grand Prix in Sochi on September 29.