Sebastian Vettel made it a clean sweep in practice for the Singapore Grand Prix to make him favourite for pole going into qualifying.

After winning this race from pole last year, Vettel is on course to at least clinch top spot on the grid for Sunday after finishing just over three tenths of a second clear of Lewis Hamilton.

Over the closing 10 minutes of the hour-long session at the Marina Bay Street Circuit as dusk fell, the drivers switched from the soft tyres to the much quicker supersoft Pirelli rubber.

Red Bull star Vettel, 38 points adrift of Ferrari's Fernando Alonso in the championship race, immediately set the benchmark with a lap of one minute 47.947 seconds, a time that was never bettered.

After going quickest in both of Friday's 90-minute sessions, it guaranteed Vettel a perfect practice run building up to qualifying.

Hamilton was forced to settle for being second quickest, 0.323secs adrift in his McLaren, with Alonso third, a further three tenths of a second down.

Force India continue to look strong at this track as Nico Hulkenberg and Paul Di Resta were fourth and seventh on the timesheet, albeit separated by 0.8secs, with the latter 1.5secs behind Vettel.

Sandwiching the duo were Lotus's Kimi Raikkonen and the second Ferrari of Felipe Massa.

Mercedes duo Nico Rosberg and Michael Schumacher were eighth and tenth, the latter two seconds adrift, with Williams' Bruno Senna ninth.

Red Bull's Mark Webber was down in 11th, that after clattering a wall at one stage which punctured his rear-right soft tyre, with McLaren's Jenson Button a lowly 12th, 2.5secs down.