Ole Gunnar Solskjaer hailed Brandon Williams as Manchester United's man of the match following their first away win in 232 days at Partizan Belgrade.
Williams, 19, earned the 41st-minute penalty that Anthony Martial converted to secure United's first victory in regulation time since their opening Europa League group game at home to Astana.
Solskjaer started Williams at left wing-back in a 3-4-1-2 formation after the Harpurhey defender made his full debut in the goalless draw with AZ Alkmaar earlier this month.
James Garner, 18, earned his first senior career start in central midfield but Solskjaer reserved special praise for Williams and believes the full-back will develop into a 'top, top player'.
"They did excellent," Solskjaer said. "I thought Jimmy just grew and grew into the game, became better and better. And Brandon was, for me, man of the match. He's been fantastic in the few games he's played, the boy has no fear, he's as brave as a lion and he got us the win.
"In games like these when we get the first goal, we need to learn when to get the second and when to get the third. I thought today we had loads of opportunities to make sure we're in a comfortable lead, but didn't play that pass forward.
"But Brandon has an absolutely great attitude, the boy is gonna be a top, top player."
United also kept a third consecutive clean sheet in the Europa League ahead of three consecutive domestic away games at Norwich, Chelsea in the League Cup fourth round and Bournemouth.
Solskjaer still saw room for improvement in defence. "We defended really well in the box, especially. I think we showed some grit in that respect.
"We could've defended better up front, we should have stopped them, they pushed us back, we need to get more intensity in our pressing. But proud and we kept another clean sheet."
