MEMPHIS, Tenn. -- Kei Nishikori of Japan came to Tennessee wanting more matches to help him keep up his strong start to 2014. He's leaving with his fourth career title after successfully defending a championship.
Nishikori repeated as champion at the U.S. National Indoor Tennis Championships, beating Ivo Karlovic of Croatia 6-4, 7-6 (0) on Sunday. He made this his first successful title defense, taking the $103,100 winner's check and 250 points on the ATP Tour at The Racquet Club.
"It's amazing actually first time to defend title and especially here," Nishikori said.
"I had a great memory last year playing great, and today was perfect. I think I started well. There was a couple matches before I was kind of slow start. Today was different, and it wasn't easy because he had a lot of aces ... not many chances to break. I have to stay calm and stay focused to whole end of last tiebreak. Yeah, I was really happy to defend."
Nishikori, who came in ranked 16th in the world, was given a wild-card entry into this tournament, which was a 500-point event a year ago when he won here. He rewarded the decision by improving to 11-2 this year and becoming the first back-to-back winner since Tommy Haas won in 2006 and 2007.
"Win this title, that's nothing better than this," Nishikori said. "I'm really happy."
Karlovic came in having not been broken even once this week and looking for his sixth career title. The big-serving Karlovic and his 20 aces couldn't counter Nishikori's precision over 90 minutes. Nishikori saved both break points he faced while winning 86 percent on his first serve (38 of 44).
"He returned really well," Karlovic said. "I was not hitting as wide as I usually can, but he was really fast. He was returning well, and then he won. He was a little bit better."
American Eric Butorac and Raven Klaasen of South Africa beat Bob and Mike Bryan 6-4, 6-4 for the doubles title. It's the second time this year Butorac and Klaasen have beaten the Bryans after knocking them out of the Australian Open in January.
The 6-foot-11 Karlovic came into the final having gone 42 games here without being broken. Nishikori broke him in the third game of the first set playing a few steps back from the baseline to better handle the powerful first serve.
Karlovic kept going to the net with Nishikori popped a backhand past the Croat into the corner for the advantage after pushing the game to deuce. Then Nishikori broke him with a backhand passing shot past Karlovic for a 2-1 lead.
Nishikori played very efficiently, not losing a point off his serve until the eighth game of the first set when up 30-0.
The top seed fought off two break points before serving up an ace for the advantage, and Karlovic hit a return long as Nishikori held serve for a 5-3 lead. Karlovic didn't make it easy as Nishikori finally converted on his fourth set point to take the first set in 40 minutes on a Karlovic backhand into the net.
In the second set, Karlovic found himself again having to hold his serve. He faced five break points and double-faulted twice before finally taking advantage of a Nishikori return that went wide before Karlovic won the game with an overhead shot.
Nishikori dominated the tiebreaker from the start, hitting a passing shot past Karlovic for the mini-break. Karlovic hit forehands long on the next two points.
"He was really fast, and he hit two like mishit and it was in," Karlovic said. "And I just didn't have my first serve in. That's where he really took the opportunity."
Nishikori beat Karlovic with a passing shot off his forehand putting up him 5-0 that he celebrated with a fist pump. Then Nishikori finished off the match with a forehand into the corner before Karlovic hit a return long.