Webber earned back-to-back wins for the first time in his career, and a second successive one-two ahead of much-fancied team-mate Sebastian Vettel, with a composed drive amid chaotic scenes in Monte Carlo.
Reigning champion Jenson Button was one of 12 drivers who failed to finish, costing him his lead in the standings, as the safety car was called out on four separate occasions.
“It was absolutely incredible and for sure one of the greatest days of my life today,” said Australian Webber, who celebrated in the pool on board the team’s boat.
“To win here was very special. It started yesterday with qualifying when it went well, but here it is such a test for two hours.
“I had a lot of work to do, the track changed a lot – backmarkers and a lot of safety cars, getting restarts and tyre pressures right – all the basics that could test were in front of you today.”
Webber, who won from pole as he had seven days earlier in Barcelona, is level at the top of the standings with Vettel on 78 points, but leads his German colleague by virtue of having won more races. Renault’s Robert Kubica took third, with Ferrari’s Felipe Massa fourth and Englishman Lewis Hamilton fifth in his McLaren.
Michael Schumacher’s disappointing return to the track continued as he was penalised 20 seconds, relegating him to last place, for illegally overtaking sixth-placed Fernando Alonso as the safety car returned to the pits on the final lap.
Button’s miserable afternoon saw him drop to fourth in the championship, eight points behind Webber, while team-mate Hamilton is seventh, a further 11 points adrift.
PODIUM | MONACO GP TOP THREE
1. Mark Webber, Red Bull 1:50:13.355
2. Sebastian Vettel, Red Bull 1:50:13.803
3. Fernando Alonso, Ferrari 1:50:15.030
STANDINGS | DRIVERS’ CHAMPIONSHIP
1. Mark Webber, Red Bull 78pts
2. Sebastian Vettel, Red Bull 78
3. Fernando Alonso, Ferrari 75