Croatia’s Ivo Karlovic became the oldest ATP winner since Jimmy Connors in 1989 when he captured the Delray Beach Open final on Sunday.

The 35-year-old used his prodigious serve to break American opponent Donald Young three times for a 6-3 6-3 victory on the Florida hardcourt.

Karlovic, who turns 36 on February 28, is the oldest winner since Connors won in Tel Aviv at the age of 37, according to the ATP.

It is Karlovic’s sixth career title and it keeps the event in Croatian hands following last year’s victory by Marin Cilic, who later in the season won the US Open.

“It is really satisfying. At my age to do this is an unbelievable feeling and this gives me a boost of confidence to go into other events,” Karlovic told reporters after beating Young in 69 minutes.

Karlovic does not know how long he can continue at such a high level, but says he is as fit as when he was in his late 20s.

“I am healthy,” he said.

“I feel fast, strong. I don’t know how many more years I can do this but for now I am feeling good. In all the tests I am like eight years ago.”

The 6-foot, 11-inch (211cm) Croat used his height to pound 91 aces for the tournament and remained unbroken in 56 service games, though he came closest to dropping serve when he was down 0-40 in the eighth game of the first set against Young.