Wrexham beat 10-man Manchester United 3-1 but the newly promoted League Two club’s victory was overshadowed by an injury to talisman Paul Mullin.
Mullin, 28, suffered a punctured lung in a collision with goalkeeper Nathan Bishop, part of a United side mostly comprised of Under-21 players.
Goals from Elliot Lee, Aaron Hayden and Sam Dalby sealed victory for Wrexham.
Marc Jurado scored in first-half injury time for United, who had Dan Gore, 18, sent-off shortly after the restart.
Ryan Reynolds was unable to attend but Wrexham co-owner Rob McElhenney was present as Phil Parkinson’s side earned a memorable win in front of a sold-out 34,248 crowd at Snapdragon Stadium in California.
United boss Erik ten Hag, whose senior players have travelled on to Texas before tomorrow’s match against Real Madrid, watched his youthful side’s performance from the bench.
The Premier League club’s starting line-up also featured the experienced Jonny Evans, who has returned on a short-term deal after leaving Leicester City at the end of last season.
Striker Mullin, who scored 46 goals in all competitions as Wrexham ended a 15-year absence from the football league last season, required lengthy treatment before walking off the field with an oxygen mask around his neck early in the first half.
Lee opened the scoring after 29 minutes and Hayden headed in a second seven minutes later – but 19-year-old Spaniard Jurado’s side-footed finish halved the deficit.
United’s Gore was dismissed after receiving a straight red for a tackle on Andy Cannon early in the second half, before Dalby headed in Wrexham’s third from close range.