Six years after winning his first title on the men’s pro tour at the Hall of Fame Tennis Championships, unheralded Rajeev Ram returned to the scene of that 2009 triumph and won again.

In a taut duel that lasted 2 hours and 23 minutes at the Newport Casino on Sunday, Ram upset second-seeded Ivo Karlovic of Croatia, 7-6 (5), 5-7, 7-6 (2), before a near-capacity crowd of about 3,700 on a breezy, steamy afternoon.

“The first win was more elation. This one is more satisfaction just because I did it again,” the 31-year-old from Carmel, Ind., said.

Ram is the first player in the 39-year history of the tournament to beat the top two seeds. He stopped No. 1 John Isner in the first round, 6-7 (5), 6-3, 7-6 (10-8).  He also upset No. 5 Adrian Mannarino in three sets in the quarterfinals.  The second and third sets were tiebreakers.

Ram won six of the seven tiebreakers he played in his five matches and was brilliant in the third-set tiebreaker that decided the championship. He volleyed a winner, made two spectacular returns and served a pair of aces.

“That last tiebreaker was as good as I can play. One return winner, two aces, another good return, all first serves, I think. . . . For some reason I stepped up in the breakers this week,” the 31-year-old from Carmel, Ind., said after collecting his winner’s check for $84,250.

Karlovic, 36, was runner-up for the second consecutive year. Lleyton Hewitt beat him in 2014.

“I didn’t do any errors. He guessed where I was going to go and hit unbelievable returns.  That’s what it’s all about in the crucial moments.  Congratulations,” the 6-foot-9 Croat said.

The pivotal shot occurred at 1-1 in the third-set breaker. Karlovic blasted a 136-m.p.h. serve, Ram lunged, somehow got his racquet on the ball and returned a backhand that landed at the baseline.

“To come up with a winner on that guy’s serve, for me that was the shot of the tournament,” the champ said. Karlovic served 19 aces in the match. Ram hammered 17.

“He was there and made an unbelievable shot. There’s nothing to say about it,” Karlovic said.

Ram’s ranking will improve to about 86 on the ATP World Tour on Monday. He now has a spot in the U.S. Open later this summer.

Ram’s victory, followed by Jonathan Marray’s and Aisam-Ul-Haq Qureshi’s super-tiebreaker win over Nicholas Monroe and Mate Pavic drew the curtain on Newport Tennis Week. The top seed, Isner, bowed in the first round; the local favorite, Jared Donaldson of Chepachet, won in the first round; three tennis greats, former No. 1 Amelie Mauresmo  of France, wheelchair star David Hall of Australia and longtime contributor Nancy Jefferts of Dallas were inducted into the Hall of Fame, and Hall of Famer Billie Jean King received a special Hall of Fame ring. Rain delays were minimal, the weather was generally comfortable, and the grass courts held up. All in all, it was a great week of tennis at the historic Newport Casino.

Mike Szostak covered sports for The Providence Journal for 36 years until retiring in 2013. His career highlights included five Winter Olympics from Lake Placid to Nagano and 17 seasons covering the Boston...