Ferguson claimed Van Persie’s second, a volley beyond Brad Guzan after latching on to Wayne Rooney’s 40-yard pass, was the ‘goal of the century’.
The United chief said: "Never mind goal of the season, it could be goal of the century. He did something similar for Arsenal, he’s a special talent for sure. He has been unbelievable all season.
"For the first six months he was incredible, but he had that little dry spell. I knew when he scored the penalty (at Stoke) that he was back. He has been truly unbelievable. Van Persie was such a great player for Arsenal that when he became available at the end of his contract and we went for him, we knew he would make a fantastic contribution.
"In terms of impact he has made as big an impact as Cantona — he was an impact player. I have been very lucky with strikers and I’ve probably had 10 great strikers.
"I think we had an expectation with him. He was sensational with Arsenal. When we concluded the deal Arsene said he was a better player than even I thought. He was right."