Fernando Alonso on Saturday morning badly damaged his Ferrari in the last practice session before qualifying.
The Spaniard, who had been fastest in Thursday’s two preceding practice sessions, smashed into the barriers at Massenet, causing both right wheels to break off.
On his return to the paddock on foot, Alonso admitted to BBC radio that the accident was his mistake.
Also on the edge of an accident in the 60-minute session, which finished with just two hours to go before qualifying, was the sister Ferrari, even though Felipe Massa clocked the second fastest time.
The Brazilian almost hit the wall at least twice; once exiting the Swimming Pool chicane, and also when he ran wide at the Loews hairpin.
Adrian Sutil’s Force India needs a new rear wing after he spun into the barriers at Casino Square, while Michael Schumacher and Vitaly Petrov had to hit reverse gear after running into escape roads.
Robert Kubica emerged from the session with the fastest time.
“Anything can happen, especially here in Monaco, and things change very quickly in Monaco,” he said after also impressing on Thursday.