"Obviously I was down in the third set I decided to play aggressive as I could on the forehand. I would have like to have had a better serve, it would have made like a bit easier."
The tiebreak was watched by a capacity crowd on the new No5 court where Erakovic impressed with a number of forehand winners.
"It was tough . I just tried to keep calm and just tried to move on. I lost my serve and she had the break and I just through I'd chip away. I tried to play smart and work the points."
Kuznetsova had the misfortune to double fault on match point leaving Erakovic to throw her racquet in the air for what is one of her better Grand Slam victories and her first at the US Open.
She will now play another Russian, Elena Vesnina ranked 56 in the second round. The pair have played four times with matches shared. The last time they clashed was in 2012 in Budapest with Vesnina the winner on that occasion.
"She (Vesnina) hits a really flat ball and has a very good backhand. My game is not going to change against her. I'll work on my serve, but just be solid," says Erakovic.
Kuznetsova is a two-time major champion: She won titles at Flushing Meadows in 2004 and at the French Open in 2009.
Erakovic, meanwhile, has never been past the third round at a Grand Slam event and was 0-4 at the U.S. Open until Tuesday.
Kuznetsova was asked whether this year's tournament was special to her, because it is the 10th anniversary of her title in New York.
"I didn't care," she replied. "It's one more U.S. Open."
