Manchester United goalkeeper Andre Onana made two bad errors as hosts Galatasaray twice fought back from two goals down to earn a thrilling 3-3 draw on Wednesday and leave the English side's hopes of reaching the Champions League last 16 in serious doubt.
Alejandro Garnacho, Bruno Fernandes and Scott McTominay scored for United in a breathless game, but Erik ten Hag's team remain bottom of Group A on four points from five matches.
The three-time European champions' hopes of advancing are now out of their hands. United must now beat German champions and group winners Bayern Munich at Old Trafford in their final game and hope there is a draw between Galatasaray and Copenhagen.
The visitors roared into an early 2-0 lead through Garnacho, fresh from his spectacular overhead strike at Everton, and a stunning shot by Fernandes before Hakim Ziyech pulled one back from a free kick following an error by Onana.
McTominay put United 3-1 up soon after halftime but their cushion was short-lived as Ziyech slotted home another free kick under the arm of Onana and Muhammed Kerem Akturkoglu equalised for Galatasaray in the 71st minute.
Galatasaray welcomed United to RAMS Park by spelling out "Welcome to Hell" at one end of the stadium and it definitely was for Onana.
The game for United was a virtual repeat of their Champions League group clash with Copenhagen in which they gave away a commanding lead. The end-to-end match saw 17 shots for United and 16 for Galatasaray, many in the dying minutes as both sides pushed for victory.
Fernandes had a chance to become the hero, but his 85th-minute effort struck the post.
Andy Mitten has provided his Manchester United player ratings in the photo gallery above. To move on to the next slide, click on the arrows or swipe if using a mobile device.