Galatasaray remains on course to join Manchester United in the Champions League knockout phase after Burak Yilmaz secured a 1-0 victory over the already-qualified leaders on Tuesday.
Yilmaz, who headed in from a corner at the start of the second half, has scored all five goals in Group H for Galatasaray.
"We should have switched on and dealt with the ball," United defender Phil Jones said after his first appearance of the season. "We got punished on a set-piece. It's not our game. We still had chances to go on to draw."
But Galatasaray held on to remain in second place ahead of CFR Cluj on goal difference with one game remaining after the Romanian champions beat Braga 3-1. Galatasaray is at Braga on Dec. 5.
"We deserved this victory," Galatasaray coach Fatih Terim said. "We dominated the game and in the end found the goal that we needed. When you play against a team like Manchester United, you cannot go slowly. You have to be enthusiastic and wise.
"I am fortunate my players were able to be both things this evening."
United's run of four straight wins only came to an end after manager Alex Ferguson left key players at home for the trip to the intimidating Turk Telecom Arena in Istanbul.
"I think they handled the atmosphere and the temperament was good," Ferguson said. "They handled that OK. Parts of the game were good but the area in which we were worried about — set-pieces — we suffered. That was always going to be a worry for us.
"Other than that, I was satisfied and it was a decent performance. We had some good attacking play in the first half and at that point the only trouble they gave us was from outside the box."
On his first start of the season, United midfielder Nick Powell came close to scoring in the first half, powering a header against the crossbar from Tom Cleverley's corner.
With Jones solid throughout in defense after returning from back and knee problems, United goalkeeper Anders Lindegaard had only one notable save to make in the first half, turning away a curling effort from Hamit Altintop.
But there was more pressure from the Turkish hosts after the break, with Lindegaard blocking Albert Riera's long-range effort and doing well to tip over Felipe Melo's firm header.
But Lindegaard was beaten in the 54th when Yilmaz found space on the edge of the six-yard box to head Selcuk Inan's corner into the net.
United has conceded the first goal in 12 out of 17 Premier League and Champions League games this season.
The crossbar ensured it wasn't a heavier loss with Altintop striking against the woodwork.