Certainly the tyres on the leading cars were about done for the day, and Chilton and Gutiérrez were in next time around for new sets. Ericsson was in the following lap with van der Garde and Razia, and now that left Cecotto and Valsecchi well out in front but exposed to their rivals having superior speed on their new tyres once they came out. Cecotto responded to the danger at the end of lap 23, but Valsecchi was toughing it out and remained on track, replying on his proven ability to make his tyres last longer than the others.
Behind Valsecchi, the next four had resumed in the same order following their pit stops - Cecotto, Ericsson, van der Garde and Chilton. Stefano Coletti was in sixth, the Scuderia Coloni cars having been alone in choosing to start the race on the longer-wearing prime tyres. Then it was Palmer still ahead of Gutiérrez, while Luiz Razia had come out of the pit stops the worst and fallen back multiple positions to slot in behind the Lotus just ahead of Nigel Melker in the Ocean Racing car, who also had yet to make his mandatory pit stop.
Valsecchi finally called time on his tyres at the end of lap 24 and came into the pits: but his gambit had worked, and he had effectively climbed three places when he rejoined the track in fourth place just ahead of Chilton. Coletti made his harder tyres last almost the entire race, finally pitting with four laps to go but unfortunately having a slow stop with a problem with his rear right wheel changer that dropped him down to tenth place.
Another late visitor to pit lane was Esteban Gutiérrez, who has stumbled over the still-too slow Venezuela Lazarus GP car of Crestani coming out of the tunnel on lap 37 and ended up cutting the chicane, bouncing over the kerbs and losing traction, ending up swiping the outside barrier and shattering his front wing. Luiz Razia was also caught up in the incident and also ended up pitting, dropping him well out of the points.
Up front, Cecotto was still in front of Ericsson, who was toying with him by pulling up close to the rear of the Addax car and then dropping back, seeking to unsettle the youngster and to probe for weaknesses. Cecotto remained unfazed, and Ericsson could find no way past on the tight and twisting road course. In the end, Cecotto's nominal winning margin across the finish line was 0.5s over Ericsson and he got to head up onto Monaco's unique trackside podium - the second impressive motor sports victory for a Venezuelan in under fortnight, and the first of 2012 for reigning championship-winning team Barwa Addax.
Van der Garde was some way off the leading duo, but comfortably safe in third position over ten seconds ahead of Valsecchi, despite the DAMS setting some blistering late fast laps in an effort to cut the gap. Chilton clung on to fifth place in the end ahead of Palmer who will be relieved to have made a full race distance with no technical gremlins, while James Calado's early tyre change gamble had paid off after all with seventh place putting him on the front row of the Saturday sprint race under the reverse grid rules, alongside local boy Stephane Richelmi who finished the feature race in eighth in the Trident to claim the sprint pole.
In his latest brush with penalty-wielding race stewards in this year's GP2 season, Fabio Leimer was hit by a late drive-thru for failing to respect track limits on lap 34 that dropped him down to 18th place at the end. Coloni's Fabio Onidi retired on lap 26 on the run into Massenet, seemingly after having clipped the barrier through the tunnel on the previous lap. There was no "seemingly" about Nigel Melker's own hit against the barrier in the tunnel on lap 33 that left his suspension bent all out of shape, and the Ocean car stopped on track at turn 11.
Relative new boy Victor Guerin recovered from stalling on the formation lap grid and having to start from the pit lane to finish in a creditable 16th place - first man off the lead lap - by the end.
Full race results and times