Christian Pulisic become the first American to score in a Champions League semifinal but Real Madrid forward Karim Benzema cancelled out the Chelsea goal in a 1-1 draw in Madrid.
Pulisic's away goal may prove to be the difference when the two sides head to Stamford Bridge next Wednesday, but the Blues may come to rue their missed chances after controlling the tempo throughout most of the match.
With the start, Pulisic became only the third American player to feature in the Champions League semifinals after Tyler Adams and DaMarcus Beasley.
Pulisic led the line alongside Timo Werner, who scored his first goal in the last 15 games against West Ham on Saturday, but their runs into the box in the first five minutes didn't seem to bother Real.
The duo nearly combined for the opening goal in the 10th minute. Mason Mount led a counter-attack down the left wing and his deflected pass found Pulisic at the far post. The American deftly passed to an open Werner in front of goal but former Chelsea keeper Thibaut Courtois made the save to keep things scoreless.
But Pulisic took matters into his own hands in the 14th minute when he latched onto a lofted pass from Antonio Rudiger. The former Dortmund star danced around Courtois with a beautiful dribbling display and finished coolly for what could be a critical away goal.
Benzema came within inches of equalizing in the 23rd minute when he sent a rocket from just outside the box that easily beat Chelsea keeper Edouard Mendy before hitting the post and ricocheting out of play.
Pulisic continued to lead the charge, drawing four defenders around the penalty area in the 25th minute, before laying off a pass for Ben Chilwell as the left-back fired wide.
But Benzema eventually got his equalizer in the 29th minute with a touch of magic for his 28th goal of the season. In the chaos of a set-piece play, the Frenchman headed down a pass right in front of goal and smashed in into the net on a volley before any Chelsea defender could even step to him.
Werner had another chance in the 43rd minute when Pulisic sprung his run with a pass down the wing, but the summer signing from RB Leipzig blasted his shot into the side-netting.
The German international kicked off the second half with a chance in the 48th minute after N'Golo Kante won another ball in Real's defensive third, but Werner's hesitation allowed a Real defender to step in for the block.
Already on a yellow, Pulisic's night ended in the 66th minute when the goalscorer was subbed off for Hakim Ziyech. Eden Hazard came on a minute later in the hopes of striking a crucial blow against his former side.
Benzema tried to put the hosts ahead in the 76th with a leaping effort on a volley at the edge of the area, but Kante and Reece James threw themselves at the chance and blocked the effort.
In the 88th, Toni Kroos saw his low shot deflected and fly just past the post. On the subsequent corner, Varane's header deflected off the face of a Chelsea defender and nearly missed the opposite post.
Both sides played to a cautious end in the second half as Chelsea will take an away-goal advantage back to London with Real Madrid expected to have Sergio Ramos back in the team next week.
Here were the lineups for both clubs:
The winner of this semifinal tie will play either PSG or Manchester City for the 2021 Champions League title. The final is set for May 29 in Istanbul.
More Soccer Coverage: