Costa Rican forward nutmegged Michael Carrick before curling home from distance, and impressed as Olympiakos comfortably defeated the Manchester giants
Maybe it's the reason Arsene Wenger refused to shop for attacking reinforcements in January.
He knew just what he had in young Costa Rica attacker Joel Campbell.
And now, Manchester United, and the whole of Europe know too.
With Moyes' United already losing 1-0 to a deflected Alejandro Dominguez strike in the first half, and yet to register a shot on target, Campbell received the ball some 30 yards out from David de Gea's goal, nutmegged Michael Carrick, and then curled a wonderful effort past the Spaniard and into the bottom corner.
If the Arsenal loanee, who was awarded a work permit to play in England last summer, wanted to play his way into Arsene Wenger's plans for next season he could do little more, with the goal the highlight of an impressive display.
There were rumours that Arsenal were open to discussing a permanent transfer to Olympiakos for the youngster ahead of the fixture, but that may be something Wenger chooses to reconsider given his performance as the Greeks emerged 2-0 winners.
Playing from the right side of the attack, he will have plenty of competition should he remain at Arsenal for the 2014-15 season, but by the looks of it, he is more than good enough to turn out against top Premier League opposition.
Campbell has 10 goals and 10 assists for the Greek champions this year, following less impressive spells at Lorient in Ligue 1 and Real Betis in La Liga.
He also has 8 goals in 30 games for his country, and despite being 21-years-old, will likely be central to Costa Rica's attacking threat in this summer's World Cup, alongside Fulham forward Bryan Ruiz, who is on loan at PSV.
image: © wonker