France midfielder Pogba scored a penalty and curled in from distance to take his tally to three goals since his world-record £89m ($109.1m, €100m) return from Juventus.
Anthony Martial, with another penalty, and Jesse Lingard were also on target as Jose Mourinho’s team secured a win that left them level on six points with Feyenoord at the top of Group A.
Fenerbahce replied late on through United old boy Robin van Persie, who tucked in a cross from substitute Emanuel Emenike and was rewarded with applause from all four corners of Old Trafford.
The result vindicated Mourinho’s decision to make seven changes to the team that had held in-form Liverpool to a 0-0 draw on Monday.
Dropped for United’s last 3 games, captain Wayne Rooney returned up front to face the team against whom he scored a memorable debut hat-trick in a 6-2 Champions League win in September 2004.
