Marin Cilic has won the St Petersburg Open final with a 7-6 (7-3) 4-6 6-4 victory over American Taylor Fritz in a gruelling contest lasting two hours and 23 minutes.

The 33-year-old Cilic clinched his second title in St Petersburg. He previously won in 2011.

Sunday's was his fourth title in Russia after two wins in 2014 and 2015 in Moscow, where he also lost the final last week.

"Coming 10 years after winning in 2011 and also winning now, it's so, so special for me, especially this part of my career," said Cilic. "Having now a family, two sons, I want to absolutely dedicate this trophy to my newborn son."

The Croatian is the sixth active player to reach 20 tour-level titles after Roger Federer (103), Rafael Nadal (88), Novak Djokovic (85), Andy Murray (46) and Juan Martin del Potro (22).

Fritz, who celebrated his 24th birthday by beating compatriot Tommy Paul on Thursday, saw Cilic save a break point in the final set with a daring drop shot.

Cilic took advantage of Fritz's double-fault on break point at 4-4 to serve for the match, winning with a forehand volley.