Kei Nishikori of Japan advanced to the final of the U.S. National Indoor Championships when Australian Marinko Matosevic retired Saturday with a blistered right foot after losing the first set 6-4.

Nishikori will play either Feliciano Lopez of Spain or Denis Istomin of Uzbekistan on Sunday looking for his third career title and first since winning in Tokyo last October. No. 5 Nishikori was the only seed to advance out of the quarterfinals after he ousted top-seeded Marin Cilic of Croatia.

Matosevic led 2-0 before Nishikori broke back, and the 23-year-old player broke Matosevic again to go up 4-3. Matosevic then called for a trainer to bandage the ball of his right foot.

Nishikori served out and won the set in 37 minutes. Matosevic then retired.