MONTE CARLO, Monaco - Ferrari's Felipe Massa crashed heavily in an accident-strewn final 2013 Monaco Formula 1 GP practice session on Saturday with Nico Rosberg completing a sweep of fastest times for Mercedes.Massa wrestled with a seemingly unresponsive steering-wheel before locking his brakes and smashing into the steel guardrail on the pits straight.The Ferrari then plunged nose-first into the energy-absorbing plastic safety barrier at the Devote corner, bringing out red flags with 23 minutes remaining and leaving Massa's mechanics with a major repair job before later qualifying.HAT TRICK FOR ROSBERGThey were not the only ones handed an increased workload. Force India's Adrian Sutil hit the barrier at Massenet on the rise to Casino Square with 15 minutes remaining.Rosberg, fastest in both sessions on Thursday - Friday being a rest day - will be chasing a third pole in a row. He completed one hat trick with a quickest lap around the narrow street circuit of 1min14.378. That was 0.661 faster than second-placed Grosjean's best and 0.883 faster than Red Bull's triple Sebastian Vettel in third place.Ferrari's Fernando Alonso was fourth fastest, 0.908 off the pace - but without doing a clean lap on the fastest tyres - ahead of qualifying for a race he has won twice for different teams.GLAMOUR HIGHLIGHTRosberg's team mate Lewis Hamilton was fifth on the time sheets.Monaco, the glamour highlight of the F1 calendar, is the sixth race of the season. Vettel is leading Lotus's Kimi Raikkonen by four points.Raikkonen was sixth quickest on a chilly but bright morning with a gusty breeze blowing in from the sea and across the yacht-filled harbour.Times from 2013 Monaco F1 GP third practice1 Nico Rosberg (Germany) Mercedes 1min14.3782 Romain Grosjean (France) Lotus 1min15.0393 Sebastian Vettel (Germany) Red Bull 1min15.2614 Fernando Alonso (Spain) Ferrari 1min15.2865 Lewis Hamilton (Britain) Mercedes 1min15.3116 Kimi Raikkonen (Finland) Lotus 1min15.3807 Mark Webber (Australia) Red Bull 1min15.5508 Paul Di Resta (Britain) Force India 1min15.5949 Pastor Maldonado (Venezuela) Williams 1min15.86110 Nico Hulkenberg (Germany) Sauber 1min15.92611 Sergio Perez (Mexico) McLaren 1min15.95812 Jenson Button (Britain) McLaren 1min15.97613 Jean-Eric Vergne (France) Toro Rosso 1min15.97614 Daniel Ricciardo (Australia) Toro Rosso 1min16.06015 Adrian Sutil (Germany) Force India 1min16.06816 Felipe Massa (Brazil) Ferrari 1min16.10517 Esteban Gutierrez (Mexico) Sauber 1:16.427 18 Valtteri Bottas (Finland) Williams - 1min16.93319 Charles Pic (France) Caterham - Renault 1min17.90220 Giedo van der Garde (Netherlands) Caterham 1min18.10221 Jules Bianchi (France) Marussia 1min18.70622 Max Chilton (Britain) Marussia 1min19.228 Stay with Wheels24 for the 2013 Monaco F1 GP weekend.