The goal completed a remarkable sequence of goals during United’s four-match tour of Australia and Asia, with all nine either scored or assisted by a player who has been developed by their academy.
It was not all good news for United though, as central defender Eric Bailly left the field on a stretcher with what looked like a serious ankle injury.
Anthony Martial had given United a deserved half-time lead with a shot that went through Paulo Gazzaniga’s legs.
But Spurs were the better side after the interval and levelled through Lucas Moura’s deflected shot.
The game seemed destined for penalties until 18-year-old Gomes beat two defenders inside the penalty area and fired home.
United forward Martial looks a player reborn on this trip.
From being a player who some suspected would not respond to manager Ole Gunnar Solskjaer’s harder pre-season training regime, the France international has been electric at times.
With Romelu Lukaku’s intended move to Inter Milan dragging on, leaving the Belgian in limbo and not playing, Martial and Marcus Rashford have filled the central striker role.
Martial in particular has been a more consistent threat in that position than he has tended to be out wide.
He almost scored early in the contest, his curling shot bouncing out off the inside of Gazzaniga’s far post.
Martial’s goal required a large degree of good fortune, though, as his shot went through the legs of Gazzaniga, who will have been disappointed to concede at his near post after Andreas Pereira had exchanged passes with Mason Greenwood before setting up the shooting chance.
It put him level with Rashford and Greenwood as the club’s top scorers on the trip that has yielded four wins.
It was a feisty affair with Pereira and Dele Alli both booked.
And though Moussa Sissoko avoided a caution for his crude challenge on United winger Daniel James, it was bad enough to bring a reaction from Scott McTominay as the two sets of players came together.
Bailly’s injury was accidental though. The Ivorian was clearly in pain when he was carried back to the dug-out area. Solskjaer came to offer sympathy before Bailly hopped down the stairs towards the dressing rooms.
Given the former Villarreal man had his season ended early by a knee injury in May that stopped him going to the Africa Cup of Nations, it is sadly proving to be an unlucky time for Bailly.
United fly straight home after the game and will play Solskjaer’s former club Kristiansund on Tuesday.
More to follow.