Nico Rosberg beats Lewis Hamilton in Singapore first practice

Nico Rosberg had the edge on Mercedes team-mate Lewis Hamilton throughout the first practice session at the Singapore Grand Prix.

The German ended up 0.319 seconds clear of Hamilton, who heads into the race with a comfortable 53-point lead in the world championship with seven events to go.

Hamilton was just 0.017secs quicker than the Red Bull of Daniel Ricciardo in third, ahead of Ferrari's Sebastian Vettel.

McLaren looked more competitive than of late, with Fernando Alonso 11th fastest.

The Spaniard's team-mate Jenson Button was 15th, 0.3secs adrift around the challenging, long and bumpy Marina Bay street circuit.

Rosberg comes out fighting

Rosberg said that he had "nothing to lose" after his retirement from the last race in Italy left him with an almost insurmountable challenge in the championship.

Darkness falls on the Marina Bay circuit

He received another blow with the news that he had to take his fourth - and final - permitted engine for the weekend after Mercedes decided not to risk the upgraded engine that was used in Italian Grand Prix practice. It had to be taken out when a problem was discovered.

Rosberg's engine is the same specification as Hamilton's but the move means that if he runs into more trouble this season and has to take another engine, he will receive a grid penalty.

Nevertheless, Rosberg came out of the blocks oozing intent, starting practice in the way Hamilton has done so many times this year, setting times out of reach of his rivals and staying out of touch as they improved their times behind him.

Hamilton looked less comfortable, and had a couple of lurid moments as he fought his Mercedes on the slippery track surface.

Red Bull vs Ferrari

Behind the Mercedes, Red Bull lived up to expectations that they could be challenging Ferrari for best of the rest behind Mercedes this weekend with a very impressive lap by Ricciardo.

The Australian was 0.163secs quicker than his former team-mate Vettel in the Ferrari, with the German's team-mate Kimi Raikkonen fifth.

Ricciardo said on Thursday that he felt that if Red Bull started strongly they could carry that form through the weekend on a track on which the level of power of their Renault engine is not such a handicap.

Manor driver Alexander Rossi will replace Spaniard Roberto Merhi for the Singapore Grand Prix

Vettel flirted with the walls throughout the session, having a couple of near misses, including a harmless spin at Turn Five when he launched the car over the kerb.

Ricciardo's team-mate Daniil Kvyat was hit by an engine problem and managed only a handful of laps.

Tight midfield battle

As expected, there was a very tight fight for the lower points positions, featuring the Williams, Force India, Toro Rosso, Lotus and McLaren cars.

Williams's Valtteri Bottas was at the head of it - 0.6secs behind Raikkonen but less than 0.1secs quicker than Max Verstappen's Toro Rosso.

Force India's Nico Hulkenberg, Toro Rosso's Carlos Sainz and Lotus's Pastor Maldonado completed the top 10, ahead of Alonso.

McLaren are targeting a decent points finish after two difficult races on the high-speed tracks of Spa and Monza, where the inefficiency of the Honda engine's hybrid system leaves the car more than 200bhp down on the best for a large part of the longest straights.

Although the Honda also lacks ultimate power compared to the other three engines, that problem is far less a handicap in Singapore, where the straights are short enough that the Honda does not 'clip' before the end of most straights.

Bad start for Rossi

American Alexander Rossi had an unfortunate start to this career with Manor, who have drafted him in for five of the last seven races of the season in place of Spaniard Robert Merhi.

Rossi was doing well - with a fastest time of just 0.015secs off team-mate Will Stevens, who has driven the car all year - until he lost control and smashed into the barrier at Turn 18, doing considerable damage to the right-hand side of the car.

"I braked a bit too late in Turn 18 and it was my mistake. I felt quite comfortable in the car and the pace was OK, so we will improve on that for tomorrow."

Practice results

Singapore Grand Prix coverage

Sebastian Vettel finished fourth during the first practice session