A late goal from Ferland Mendy decided a hard-fought game that swung in the visitors' favour thanks to an early red card.
So which players stood out most on the night?
✔️ GOOD PERFORMANCE
Toni Kroos: 8.5
There are, perhaps, two ways of looking at Real Madrid's performance: Either they were toothless for much of this encounter, or they wore their opponents down before scoring an inevitable late goal.
If the latter narrative appeals, then it is only right to credit Kroos for his role. The German made 138 passes (only Luka Modric got remotely close with 98) across the 90 minutes and completed a match-high 49 into the final third.
No wonder Atalanta couldn't hold on after chasing the ball around for so long.
✖ BAD PERFORMANCE
Remo Freuler: 5.3
Just what was Freuler thinking?
With only 16 minutes on the clock, the Swiss would have been better letting Mendy run beyond him rather than picking up a deserved red card for denial of a goalscoring opportunity.
That set the tone for the game and possibly the tie, with Atalanta now facing an uphill battle to turn things around in Spain.
⭐ STAR MAN
Ferland Mendy: 8.2
Things should have been far easier for Real after Mendy tempted Freuler into a daft challenge at the edge of the box with his speed of thought and touch.
As it was, the Frenchman was needed for another moment of magic at the death, and he produced it in the form of a brilliant curler from distance on his supposedly weaker right foot.
He was the reason the visitors won this game and the reason they are in control of the tie ahead of the return leg.