LONDON (Reuters) - Ivo Karlovic offered further proof that tennis careers can continue blossoming long after players reach their 30s when he became the oldest ATP title winner for 37 years at the weekend.

The 37-year-old Croat outlasted Luxembourg's Gilles Muller 6-7(2) 7-6(5) 7-6(12) to win the grasscourt Hall of Fame Championships in Newport, Rhode Island -- becoming the oldest champion in the tournament's history.

In saving three match points before downing Muller, the big-serving Karlovic became the oldest Tour winner since Marty Riessen (37 years, nine months) in Lafayette in 1979.

It was his third consecutive Newport final, having lost the previous two. Karlovic now has seven career titles, the first coming in 2009.

"After all these years when I was losing in the final and now I was finally able to do it," world number 35 Karlovic said. "And I was down a match point. That makes it even nicer."

Karlovic, who returned from a left knee injury earlier this year, became the oldest man to reach the third round of a grand slam for 25 years at this year's French Open, eventually losing to runner-up Andy Murray.

At Roland Garros, 51 men aged 30-plus began in the main singles draw -- a new grand slam record -- while there were 49 30 somethings in round one at Wimbledon.

(Reporting by Martyn Herman; Editing by Amlan Chakraborty)