Manchester United's 23-match unbeaten Champions League home run ended with a 1-0 loss to Besiktas on Thursday, sending the battle for top spot in Group B down to the final match.
Rodrigo Tello scored in the 20th minute against an under-strength Man United, which had already qualified for the knockout stage.
Tello's 30-meter shot took a slight deflection off United defender Rafael Da Silva and dipped and bounced beyond goalkeeper Ben Foster to give the Turkish club its first win in the group.
Besiktas goalkeeper Rustu made stoppage-time saves to deny Federico Macheda and Wes Brown.
United still has a three point lead over Wolfsburg and CSKA Moscow, which beat the Germans 2-1 in Moscow earlier Wednesday.
United, which will secure top spot with a draw at Wolfsburg on December 8, leads the group with 10 points. Wolfsburg and CSKA Moscow each have seven points. Besiktas has four points.
Leading the attack on Wednesday were 18-year-old forwards Danny Welbeck and Macheda.
"They have shown some really good things and that's encouraging for us," Ferguson said. "In the second half, they (Besiktas) went very defensive, they stopped the game and played out time. It's difficult for young players to understand that, but it's a good experience for them."
Ferguson claimed second-half substitute Patrice Evra should have been awarded a penalty for being fouled by Ibrahim Kas in the closing minutes.
"That is two games in a row we have had stonewall penalties in European football," Ferguson said. "It isn't in the spirit of the game but what can you do about it? You just have to get on with it."
AP