Mark Webber showed that Red Bull Racing will again be the team to beat after topping the times in the second free practice session of the Korean Grand Prix.

Having been content to allow McLaren a turn in the spotlight in the opening 90-minute session, the Australian led the way with a lap time nearly three seconds faster than title rival Lewis Hamilton managed in the morning, clocking 1min 37.942secs around the undulating Yeongam circuit.

Despite completing 'only' 23 laps, Webber ended the day just under two-tenths clear of next fastest man, Fernando Alonso, who was among those registering 30+ tours as they sought to understand the nuances of what began as a dusty ribbon of tarmac, and continued to offer little grip. Alonso's Ferrari team-mate, Felipe Massa - who ended the day sixth fastest - reported that the twisty final sector was 'undriveable' due to the lack of grip, while Williams' Nico Hulkenberg was told to make the best of what he had under him after complaining about his tyres.

Alonso, one of Webber's closest rivals, along with Sebastian Vettel, in the championship standings, narrowly failed to join the Australian in the 1min 37s, but had a tenth and more in hand over third-placed Hamilton, with a bigger gap extending back to Renault's Robert Kubica and the second McLaren of Jenson Button, who rounded out the top five.

Button's session did not go entirely smoothly, however, for, having moved to the top of the times, the Briton returned to the pits with his undertray and diffuser catching light, forcing the McLaren team to douse the rear of his MP4-25 with extinguishers. He remained in the garage until the final third of the session, but was able to return and lower his personal benchmark, despite appearing to spend a lot of his time backing off to make space on track.

Behind Massa, Vettel was unable to match team-mate Webber's pace, but slotted in at the head of a tight group comprising Vitaly Petrov and Nico Rosberg, which rounded out the top ten ahead of Sauber's Kamui Kobayashi.

Nick Heidfeld and Michael Schumacher both narrowly missed the top ten, while the two Williams drivers, who had briefly topped the times in session one slipped back to 13th and 16th, mingling with the Force Indias of Tonio Liuzzi and Adrian Sutil.

The Italian again suffered a setback, stopping out on track, but his misfortune did not warrant the red flag, unlike HRT's Sakon Yamamoto, who spun and tapped the wall in the tight 'street circuit' section approaching the pit entry, which itself has attracted some attention for its blind approach.

Lotus returned to the head of the new team division, with Heikki Kovalainen heading Jarno Trulli, who bounced back from his session one gremlins. The pair were split by a tenth, with the best Virgin entry a couple of tenths adrift.

Unsurprisingly, Bruno Senna brought up the rear, completing just three laps after his HRT was repaired following his morning session spin. The Brazilian suffered suspension failure as a result of the mishap, with the arm also puncturing the gearbox, adding to the delay.