Massa's first stop a couple of tours later still enabled the 2008 world championship runner-up to leapfrog the luckless Rosberg as well, and Webber would increase the misery in the Williams garage when he too jumped the FW31 following his own first pit visit a handful of laps further into the grand prix.
Button, though, was continuing to peerlessly maintain his lead – a commanding 17 seconds 23 laps in, albeit being gradually chipped away at by Barrichello – with Alonso coming in for the first time on lap 28, rejoining behind the Force India of former team-mate Giancarlo Fisichella and outside the top ten. Kubica's cheerless weekend reached a perhaps fitting conclusion as he climbed out of his troubled BMW F1.09 with barely 30 laps completed, leaving just 16 cars in action.
As Barrichello continued to put the hammer down in his efforts to draw himself back into the fight, Raikkonen and a hard-charging Massa behind him were being dragged along into the bargain, with Webber not altogether out of the reckoning either as sixth-placed Rosberg's challenge conversely faded. Massa set fastest lap twice in quick succession as he clearly pushed right to the ragged edge – and increasingly ramped up the pressure on team-mate Raikkonen – but in occasionally cutting the chicane in order to do so, the ten-time grand prix-winner found himself in danger of receiving a penalty.
With Button steadily managing his advantage as half-distance approached and passed, Webber was the next man to show his hand with fastest lap for Red Bull, as Raikkonen copied the 'Massa line' across the chicane. Barrichello was the first of the front-runners to pit with 28 laps left to run, followed by Button just a lap later, with the latter narrowly losing track position to new leader Raikkonen – though with both Ferraris still needing to switch over to the unfavoured super-soft rubber before the end of the grand prix, and the first of them making the change with 25 laps still to go, as Massa continued to push on.
McLaren's weekend – that had begun so brightly in Thursday practice – came to an abject conclusion when Kovalainen, pushing hard in an effort to put pressure on sixth-placed Rosberg ahead, shunted into the circuit barriers in the Swimming Pool section of the track.
With the Ferraris now on effectively the wrong tyres, Barrichello found himself liberated from much of the pressure behind and free to focus on closing the gap on Button ahead – and close it is just what he proceeded to do, reducing the world championship leader's advantage to just over twelve seconds with 19 laps to the chequered flag.
As the laps ticked down, in typical Monaco fashion the status quo went largely unchanged, with Button maintaining his lead over Barrichello and Raikkonen and Massa slowly slipping back, and Rosberg pitting from fifth with just 13 laps remaining and relinquishing places to Webber and Alonso, before the latter pitted again only a lap later. Behind them, Fisichella was doing his utmost and pushing hard in a bid to wrest the final points-scoring position away from the Scuderia Toro Rosso of Sébastien Bourdais barely a second in front of him, with Kazuki Nakajima in the second Williams holding a steady watching brief behind at the rear of the three-car train.
That squabble aside, the major interest in the closing stages was focussed on the two Ferraris, with Massa closing in on Raikkonen and Webber remaining a threat to the pair not far behind. The Australian, indeed, had closed right onto the back of the second of the Ferraris by the chequered flag, but it was not quite enough as the New South Wales native was forced to settle for fifth in the final reckoning, behind Button, Barrichello, Raikkonen and Massa.
The points-scorers were rounded out by Rosberg, Alonso and Bourdais, as Fisichella cruelly missed out by barely two seconds in ninth place for Force India following an impeccable drive, with Timo Glock, Heidfeld, Hamilton, Jarno Trulli, Adrian Sutil and Nakajima the remaining classified finishers, though the latter failed to reach the line after crashing into the barriers on the penultimate lap. There were no such errors from the race-winner.
Crash.net Driver of the Day: Giancarlo Fisichella (just missed out on registering Force India's first points after a dogged and determined drive)