MEMPHIS, Tenn. -- Japan's Kei Nishikori advanced to the final of the U.S. Indoor National Championships when Australian Marinko Matosevic retired after losing the first set 6-4.
"He was playing really well from the beginning and he broke my serve in the beginning 2-love," Nishikori said. "Lucky for me to play just one set and feel fresh for tomorrow."
On Sunday, Nishikori will face Feliciano Lopez of Spain, a 6-2, 3-6, 6-3 winner over Denis Istomin of Uzbekistan. Lopez will be seeking his third title in his eighth career ATP final after a match he thought he had won with an ace -- even preparing to shake hands with the chair umpire -- only to replay the point because of a let ruling.
"In the old times, we had one guy on the net with a finger," Lopez said. "I don't know if it's more accurate or not. The system now with the machine you never know when it's real let or not."
Marina Erakovic of New Zealand won her first singles title when Sabine Lisicki of Germany retired because of illness.
Erakovic, who lost this final to Sofia Arvidsson last year, took the first set Saturday night 6-1 in 27 minutes. During the break, Lisicki realized she couldn't continue.
"I just didn't have any energy left in the tank," Lisicki said.
Erakovic looked almost disappointed. The winner of seven doubles titles said she didn't realize Lisicki had been ill so she was shocked when the German retired and showed little joy until she was handed the guitar-shaped trophy.
"I've dreamed of winning WTA titles when I was little and for it to happen, I can just describe it as happiness and relief. Now it's been three finals and to win one, I just want to do a little dance."
Erakovic will not have the chance to defend the title, as it is the last women's tour even in Memphis. Its place on the calendar will be replaced by a WTA tournament in Rio de Janeiro.
Nishikori will be looking for his third career title and first since winning in Tokyo last October. That's when he became the first Japanese player to win on home soil in that tournament's 40-year history.
The top Asian player in the ATP rankings at No. 22, the fifth-seeded Nishikori was the only seed to advance out of the quarterfinals here after he ousted top-seeded Marin Cilic of Croatia.
"It's a tough tournament here, so I understand anything happens," Nishikori said.
Matosevic had been experiencing pain in his right foot since January. The pain reached a new level Friday after beating Alexandr Dolgopolov in three sets. Matosevic iced his foot for a few hours and found that even walking to a grocery store across from his hotel was painful.
The Aussie, the ATP's most improved player in 2012 as he jumped from No. 201 in 2011 to 49th, still tried to make it through his third appearance in an ATP semifinal.
Matosevic took the doughnut-shaped pad protecting his foot off before the match and led 2-0 before Nishikori broke back. Nishikori broke Matosevic again to go up 4-3. Matosevic then called for a trainer, who doubled up the padding on the Aussie's right foot. That simply made it too awkward.
"It's tough," Matosevic said. "I definitely felt like I could've won today, and then the bottom half, all the seeds dropping out, Istomin, Lopez, it feels like a big missed opportunity."
Lopez, whose last semifinal came in Beijing last October, reached his first final since Belgrade in May 2011.
He needed only 23 minutes to take the first set against Istomin, who had not dropped a set in Memphis until Saturday. Istomin broke back in the fourth game to go up 3-1 in the second trying to reach his third career ATP final.
Lopez had to fight to hold serve after falling behind 0-40 to open the third set and thought Istomin had broken his serve with a great lob shot. But Lopez asked for the replay, which showed the ball was just out. With the reprieve, Lopez managed to hold serve and broke Istomin to go up 4-2.