The Frenchman has enjoyed his best goalscoring season of his career under Ole Gunnar Solskjaer's guidance.
And he put in a great display as he won a penalty to help his team win 1-0 against FC Copenhagen in the Europa League quarter finals.
United now face Sevilla in the semi finals on Sunday.
"The outstanding player for me tonight was Martial," Van Persie told BT Sport after the game.
"When he switches it on he's just too fast, too silky and wow, what a player!
"He is such a joy to watch. It's like he's having a kick-about in his own garden.
"What I like about Martial is he has an eye for his team-mates – he isn't just playing for himself. He always has an eye for his team-mates and that's what sets him apart from very good players.
"That's why I think he's world-class. He can provide, he can give assists, he dribbles, he's fast but he has great awareness of what's around him."