Verstappen, who had comfortably led from pole all race, kept his head cool on worn medium tyres when a brief but intense rain shower spiced up the second half of what was shaping up to remain a lifeless Monaco race.
Having held off on making a pitstop to get rid of his old tyres because he didn't want to give up track position to the chasing Fernando Alonso on hards, Verstappen was rewarded for his patience by being able to switch straight to intermediates when the rain intensified on lap 56 of 78.
Verstappen's cause was further helped by Alonso pitting for slicks, the Spaniard taking a massive gamble to try and win the race instead of settling for yet another podium.
But Verstappen almost threw away the win by losing control of his Red Bull RB19 into the first right-hander of Portier, tapping the outside wall before gingerly heading into the tunnel.
According to Verstappen his wall tap actually helped arrest his slide as he fought to remain in control. "I locked the rears and I couldn't get out of it, so it's just trying to control it with a bit of drifting," Verstappen said.
"Luckily the wall in a way stopped it from sliding even more."
After the incident Verstappen stabilised his pace as the track started drying in the closing stages, but he admitted it had been a difficult exercise to stay out of the barriers and to delay his only pitstop as much as he did, having been put under strategic pressure from Alonso.
"It was quite a difficult one, because we were on the medium initially and Fernando was on hard tyre. We didn't want to go long but we had to stay out," he explained.
"The rain was coming, we didn't know really what was going on. The tyres were graining, it took a few laps to get through that graining phase and then the pace picked up a little bit but it was still very tricky to drive.
"It started to rain lap by lap a bit more, so we had to make the call to go onto the intermediates, but it was incredibly slippery.
"When you are that far into the lead you don't want to push too hard, but you also don't want to lose too much time, so it's quite difficult in that scenario.
"I clipped the walls a few times, it was super difficult out there but that's Monaco."
Verstappen extended his lead to 39 points on team-mate Perez, who suffered a disastrous afternoon marked by contact and four pitstops and finished two laps down in 16th.
"It's super nice to win it, also the way we did it today with the weather to stay calm and brought it home. A lot of points for the team as well, so it's great," the Dutchman added.
