Lewis Hamilton will not be "losing any sleep" over his failure to win in Singapore, the Briton's team boss Toto Wolff has claimed.

Hamilton was denied a shot at victory following a Mercedes strategy blunder during Sunday's race at the Marina Bay Street Circuit.

The world champion dropped from second to fourth as Sebastian Vettel claimed a much-needed win ahead of Ferrari team-mate Charles Leclerc, with Red Bull's Max Verstappen in third.

The result enabled the trio to reduce the championship deficit to Hamilton but, with six rounds remaining and only 156 points still to play for, the Mercedes star still holds a dominant 96-point lead over Leclerc and Verstappen, with Vettel six points further back.

Indeed, despite Hamilton's disappointing night in Singapore, the five-time world champion will head to Sochi for Sunday's Russian Grand Prix with an improved title lead of 65 points over Valtteri Bottas, after he finished one place ahead of his Mercedes team-mate.

"Lewis is strong and when you are a five-time world champion with a 96-point lead, a lead which equates to four victories, you are not losing any sleep," said Wolff.

"We are all angry. When we got together with the drivers and the engineers, there is a feeling that we got it wrong this weekend, but it doesn't mean it will have a long-term effect.

"Obviously, with the expectations we set ourselves, fourth and fifth is disappointing. The mood is one of annoyance and there isn't a single person in the team who doesn't have this feeling."

Vettel ended his 392-day wait for a race victory to deny Leclerc a third win in as many races, but the German's triumph arrived with some fortune.

Vettel was called in for tyres one lap earlier than Leclerc as Ferrari attempted to keep the 32-year-old ahead of Verstappen.

Vettel, however, took advantage of the fresh rubber, not only to keep Verstappen at bay, but to leapfrog Leclerc, too, much to the annoyance of the young Monegasque, who moaned that Ferrari's strategy was not fair.

"Two alphas competing for position has the potential for a rivalry and escalation within the team," added Wolff, who oversaw Hamilton's bitter relationship with former team-mate Nico Rosberg.

"We have been there before, but today, as a team, we are very strong with a clear philosophy. The positive is that they [the Ferrari drivers] keep taking points off each other, which is an advantage for us."