The former England captain joined the French giants at the end of the January transfer window on a five-month deal and some questioned his ability to perform at 37 years old.
But Ibrahimovic thinks Beckham is playing at the standard of more than a dozen years younger and has silenced his critics after 90 minutes in Sunday's draw at St Etienne.
Sweden star Ibrahimovic said in The Sun: "I think anybody who thought David was past his best when he signed for us is now very quiet. That man on the pitch for us looked 25.
"Central midfield is the position where you need the most energy. He showed he is not only one of the best passers in the world but that he can still be tough in the tackle and run for 90 minutes."
Former Real Madrid midfielder Beckham could also play a part in PSG's UEFA Champions League quarter-final against Barcelona in April.
And Ibrahimovic reckons the ex-Manchester United man, who won the European Cup in 1999, will be a key player.
Ibrahimovic added: "David will be so important for us in the Champions League.
"Not just on the pitch but also off it. He has so much experience of playing in big Champions League games."