The 20-year-old entered the clash at Bernabeu off the back of scoring four goals and registering three assists in 10 appearances during an impressive start to the 2024-25 campaign.
Bynoe-Gittens then got his name on the scoresheet in the 34th minute of Tuesday's game at Bernabeu, turning a low cross from Donyell Malen into the back of the net.
At the age of 20 years and 75 days old, the forward became the youngest English player to ever score against Real Madrid in the Champions League, taking the record from Alan Smith.
Indeed, Smith was 20 years and 129 days old when he scored for Leeds United against Real Madrid in March 2001, but the former forward's record has now been broken by the Dortmund star.
Bynoe-Gittens makes history in Dortmund's defeat to Real Madrid
Bynoe-Gittens was replaced in the early stages of the second period at Bernabeu, and according to WhoScored, he had three shots, made three successful dribbles and had a pass success rate of 78% during his 55 minutes on the field.
The youngster spent time with Reading, Chelsea and Manchester City during his youth career, before moving to Dortmund in 2020, and his breakthrough has come with the German giants.
Bynoe-Gittens featured on 34 occasions last season, but he has stepped up a level this term and now boasts five goals and three assists in his 11 outings during the 2024-25 campaign.
The attacker struck twice against Club Brugge in Dortmund's Champions League opener this season, before providing an assist in the team's 7-1 success over Scottish giants at the start of October.
Dortmund were undone by Vinicius magic at Bernabeu
Dortmund were 2-0 ahead when Bynoe-Gittens left the field, and if head coach Nuri Sahin had his time again, then he might well have decided to keep the Englishman on the field due to his goal threat.
BVB put themselves in an excellent position to secure a famous win at Bernabeu, but Real Madrid went on to score five times in the final 30 minutes of the match to secure all three points in impressive fashion.
Vinicius Junior scored a hat trick, while Antonio Rudiger and Lucas Vazquez also registered, with Los Blancos showing their class to turn the game around and claim the victory in front of their own supporters.
Dortmund's attention will now switch back to their 2024-25 Bundesliga campaign, which continues against Augsburg on Saturday afternoon, while their next Champions League fixture comes at home to Sturm Graz on November 5.