Koke scored Atletico’s fastest-ever Champions League goal within two minutes and Antoine Griezmann added a second after 25 before any hopes of a late Monaco comeback were ended with Radamel Falcao’s 83rd minute missed penalty.
The win meant that Atletico, who were knocked out of the group stage of Europe’s elite competition last season, advanced to the knockout stages, leading Group A with 12 points from five games.
Borussia Dortmund’s goalless draw at home to Club Bruges saw them into the next round too but Diego Simeone’s Atletico will have a two-point lead at the top of the group when they visit Bruges, and Monaco host Dortmund, in the final round of games.
Monaco are guaranteed to finish bottom of the group, having gleaned just one point.
“We needed to get through the group, and since this Champions League began, we hit the ground running because of what happened last year,” Simeone told reporters.
“Apart from in Dortmund where we fell apart (and lost 4-0) this has been a very good campaign, which is pleasing because all Champions League games are tough.
“Today, we played very well until the 70th minute, we tried to cause them damage by being as mobile as we could as they were sitting back. Then we ran out of energy and they grew into the game.”
Atletico took their early lead when Spanish midfielder Koke let fly from outside the area and watched his shot float into the net with the help of a heavy deflection from a Monaco defender.
France forward Griezmann doubled Atletico’s advantage midway through the first half, delivering a neat finish with the outside of his left boot after being teed up by former Monaco winger Thomas Lemar who had coasted down the wing with ease.
Monaco, second from bottom in Ligue 1 with only two wins in all competitions, improved somewhat in the second half as Atletico lost focus and carved out a number of chances.
They were presented with a glorious chance of getting back into the game with eight minutes remaining when Atletico defender Stefan Savic handled in the area and was sent off for a second yellow card.
But in a moment indicative of Monaco’s rotten form, Falcao, former darling of the Atletico faithful, completely missed the target from the spot at the Wanda Metropolitano stadium, which will host the competition’s final next June.
“We were very timid in the first half and their early goal didn’t help us,” said Monaco’s Henry, who is struggling in his first job as a first team coach but who can now fully focus on keeping the 2017 Ligue champions in the top flight.
“It’s a relief and a shame at the same time,” he added, talking of their failure to even make the Europa League. “We still have the game against Dortmund, but our real battle is against Montpellier and what comes after that.”