The England international left Wembley frustrated after second-half goals from Son Heung-min, Jan Vertonghen and Fernando Llorente put Spurs in command ahead of the return match in Germany on March 5.
Here, Press Association Sport analyses the 18-year-old forward's contribution for the Bundesliga leaders.
Sancho began wide on the right, supporting Dortmund's false-nine Mario Gotze. He was up against Spurs' stand-in left-back Vertonghen, with Toby Alderweireld regularly coming across to try and help nullify his threat. The youngster also had defensive responsibilities and would track back when his side were out of possession.
The teenager's nine league assists have helped propel Dortmund to the top of the Bundesliga. He very nearly added to that tally but his pin-point cross onto the head of Dan-Axel Zagadou resulted in Spurs goalkeeper Hugo Lloris impressively clawing the goal-bound header away. He earlier picked the wrong option after breaking free on the flank, with Gotze lurking in the box.
Former Manchester City man Sancho arrived at the national stadium having hit seven Bundesliga goals and one in the Champions League this season. He was primed for a 15th-minute tap-in but Chelsea-bound Christian Pulisic opted to shoot rather than pass following a mistake by Juan Foyth. He did not manage an attempt on goal before being substituted in the 88th minute.
Jadon Sancho, left, endured a difficult return to England (Adam Davy/PA)
Having already been capped three times by his country, Sancho will hope for many more appearances at Wembley. On the evidence of his first-half display that will surely be the case after he gave Spurs plenty to worry about with his pace and skill. However, Son's 47th-minute goal helped swing the momentum in the favour of Mauricio Pochettino's side and Sancho was largely anonymous in the second period and had little impact on the result.