Mason Greenwood has played his first professional football for 20 months after coming on as a substitute for Madrid-based club Getafe.
The 21-year-old, who faced attempted rape and assault allegations before all charges against him were dropped, reportedly received a generally warm welcome from home fans at the side's Coliseum Alfonso Perez stadium.
Visiting Osasuna supporters, however, shouted "Greenwood die", according to Guillermo Rai, a journalist with The Athletic.
After coming on in the 77th minute of the La Liga match, with the score at 2-2, Greenwood won two corners.
One of them led to a third goal for his new side, scored by Nemanja Maksimovic. The match finished 3-2 to Getafe.
Greenwood left Manchester United on transfer deadline day, joining Getafe on a season-long loan.
Since then, Getafe have been heavily promoting his arrival on social media.
In a video posted on X, formerly known as Twitter, Greenwood said: "Hi Getafe fans, it's Mason here. I'm so happy to be here and I can't wait to get started."
Other posts showed Greenwood coming out of the tunnel to applause from supporters in the stadium before taking part in an open training session.
Manchester United announced last month that Greenwood would never play for them again after scoring 35 goals in 129 appearances.
The club said in a statement: "All those involved, including Mason, recognise the difficulties with him recommencing his career at Manchester United.
"It has therefore been mutually agreed that it would be most appropriate for him to do so away from Old Trafford, and we will now work with Mason to achieve that outcome."
Also on Sunday, former Manchester City defender Benjamin Mendy came on for French club Lorient in the 70th minute.
The left back, who won the World Cup with France in 2018, signed a two-year deal with Lorient in July after being found not guilty of rape and attempted rape. His last game for City was in 2021.