"He's shown that really often in training. It's maybe not so easy to bring it onto the field, especially when you haven't had rhythm for a while.
"We know his quality and we saw it again today. We knew we needed a performance like that from Jadon."
But the player knows it is only half-time in the tie as Dortmund seek to reach June's Champions League final at Wembley.
"It's not over. We've still got to go to Paris and get the job done there," said Sancho.
Sancho was constantly dangerous on both flanks as well as in the middle on Wednesday, showing the quality which earned him a big-money move from Dortmund to Manchester United in 2021.
The England winger dribbled at will, carving up the PSG defence. He laid on a terrific late chance when he slid a pass to Julian Brandt on the penalty spot, with Dortmund denied by some excellent defending from Marquinhos.
Speaking with CBS Sports, Sancho credited Dortmund's 80,000-strong crowd for getting the side across the line.
"Week in week out, that's how it is. It helps us a lot. When we hear our fans we're so motivated from the start so we just can't wait to play."
Sancho said he hoped to back up the complete performance at the Parc des Princes next week.
"Hopefully I can carry on. I take it game by game. Performances like today, I hope they just carry on."
The 24-year-old, who joined Dortmund on a six-month loan in January, having been banished from the United first team by manager Erik ten Hag.
When he arrived in Dortmund, Sancho had played just three matches off the bench in the entire Premier League season, and had not taken part in a game since August.
Sancho said he had not thought about a return to Man United.
"I don't know. I'm just focused on the present right now."
