The former England captain was handed a shock place in the starting lineup but put in an impressive display during PSG's 2-2 draw in the first leg of the Champions League quarter-finals at the Parc des Princes.
Ancelotti felt that the 37-year-old did well prior to picking up an injury in the second half.
"Beckham played well," Ancelotti told Sky Sports News.
"He had a good pass at the beginning and for 30 minutes had good control of our play.
"After that he had a knock on his ankle and was not able to continue."
The return leg takes place at Camp Nou next Wednesday.