The soul singer and her record producer partner arrived at World on Wheels in California on Friday night (October 19) in a black SUV but he drove off in a lime green sportscar.
The big surprise was captured by TMZ cameras after Keys urged photographers and videographers not to ruin the moment just before she led her unsuspecting husband into the World on Wheels roller skating rink and venue in Venice blindfolded.
The couple later emerged and Swizz Beatz was left speechless as he was handed the keys to the Aston Martin outside.
As her husband sat in the driving seat of his new ride, Keys explained how she pulled off the big surprise, revealing she called on friends and had to tell a few "white lies to throw him off, because he's so nosy."
"The worst thing that was told to him was that this was sold," she said. "He was quite upset."
But the producer's birthday surprise didn't last too long - he had to dash off to the hospital after injuring his arm, which was in a sling under his hoodie.
"I'm hurt," he told TMZ cameras. "I ain't gonna lie."