The Belgium international was named on the bench for Manchester United’s home clash against Swiss side Basel in their Champions League opener.
Fellaini was brought on in the first half to replace Paul Pogba after the stand-in captain suffered a hamstring strain in the first half.
The defensive midfielder made the breakthrough with a close-range header following Ashley Young’s superb cross at Old Trafford.
Summer signing Romelu Lukaku doubled the home side’s lead with a header of his own to put Manchester United in charge.
Fellaini teed up Marcus Rashford to make it 3-0 in the final five minutes to secure three points as CSKA Moscow beat Benfica in the Group A’s other fixture.
Former Chelsea midfielder Lampard was impressed with Manchester United midfielder Fellaini in Tuesday night’s 3-0 win against the Swiss champions.
“It was a great header,” Lampard told BT Sport. “It was a great cross on the plate. It’s what Manchester United needed because they played pretty well.”
Manchester United are sitting at the top of the Premier League table despite a 2-2 draw with Stoke City at the bet365 Stadium on Saturday evening.
The Red Devils have already beaten Swansea City, West Ham United and Leicester in the Premier League so far this season.
Manchester United haven’t won the Premier League title since 2013, while the Red Devils last got their hands on the Champions League crown in 2008.
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