Arsène Wenger praised Nicklas Bendtner's "desire and heart" after his return to the Arsenal side on Wednesday night.
The Denmark international looked understandably rusty on his first appearance since August 2011 but stuck at his task and produced a fine assist for Thomas Eisfeld's second-half opener before scoring in the penalty shoot-out.
"Overall he was fantastic," Wenger told Arsenal Player.
I'm always happy when the young players show they have heart and show they are not only good football players, but they are ready to suffer to win
"He fought on his own up front for two hours tonight and he has shown that he has a desire to come back and that he has some heart. He worked very hard to come back to this level and tonight he has shown he has the quality."
Wenger watched his young side claw their way back from a 3-1 deficit in the shoot-out thanks largely to nerveless penalties from Chuba Akpom and Kris Olsson.
"I thought Chuba Akpom had a very important penalty and if he misses we are nearly out. He showed some nerves and Kris Olsson did as well," said Wenger.
"Gnabry missed but he was so tired and overall he had a great game tonight. I went for fresh, young players because they had no history of missing penalties and they were not tired, and it worked.
"I am very, very proud because we had such a young team and we played against a Premier League side with Premier League players and overall we played well.
"When we had cramps we still kept going. I'm always happy when the young players show they have heart and show they are not only good football players, but they are ready to suffer to win. That's why I'm very proud tonight."Copyright 2017 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source