Monaco Grand Prix: Nico Rosberg fastest in crash-hit third practice

Nico Rosberg topped the times for Mercedes in Saturday morning's third and final crash-hit free practice session ahead of Sunday's Monaco Grand Prix.

The 27-year-old German steered clear of much of the mechanical carnage around him in an hour of action that included four major accidents and a stoppage when Ferrari's Brazilian Felipe Massa survived a high-speed collision with the barriers that wrecked his car at Sainte Devote.

The end of the session was also halted prematurely with a second red flag, following another accident, leaving Rosberg fastest - for the third successive session in his home town - ahead of nearest rival Romain Grosjean of Lotus who, remarkably, crashed twice.

Defending triple world champion Sebastian Vettel was third-fastest for Red Bull but his time was clocked before the curtailed final minutes when the teams switched tyres.

Two-time champion Fernando Alonso of Ferrari was fourth ahead of Rosberg's Mercedes team-mate Lewis Hamilton, Finn Kimi Raikkonen of Lotus and Australian Mark Webber of Red Bull.

Massa's was the biggest accident of the session and came after 35 minutes, a crash sandwiched by two others - those of Grosjean and German Adrian Sutil - on a morning of drama in the Mediterranean principality.

The Brazilian lost control of his Ferrari car as he accelerated down the start-finish straight when it appeared that his throttle was stuck open, leaving him in a virtually helpless position.

The front wheels locked up as he slammed into the barriers at Sainte Devote at an estimated 275 kph.

It was a massive impact and looked very serious for Massa, although he was able to climb from the car and walk back to the circuit medical centre where he was declared fit and well.

Grosjean, who has managed to crash in every session to date, this time clipped the barriers as he exited the tunnel, once again giving his Lotus mechanics a busy period of repairs to the left rear of his car.

The early part of the session had seen Vettel, unexpectedly, topping the times before the accidents led to the red flag coming out.

Once the action resumed, it was not long before Rosberg took control and clocked a best lap in one minute 14.378, a full 1.5 seconds clear of Vettel's earlier effort as the teams switched to softer tyres in final preparation for the afternoon's decisive qualifying session.

Grosjean managed a fast time in 1:15.051 too but then crashed again, hitting the barriers at Sainte Devote on the outside and then sliding across the track to end up blocking the pit lane exit and effectively ending the session prematurely.