Memphis, TN (SportsNetwork.com) - Reigning champion Kei Nishikori will take on Croatian challenger Ivo Karlovic, as both men reached the final thanks to victories on Saturday at the U.S. National Indoor Championships tennis event.

The top-seeded Nishikori took care of American underdog Michael Russell, 6-3, 6-2, in a match which lasted only 64 minutes.

Nishikori, who topped Spaniard Feliciano Lopez in last year's Memphis finale, will square off against Karlovic, who won due to Yen-Hsun Lu's retirement prior to the second set of their contest.

Fourth-seeded Lu, who defeated Alex Kuznetsov 6-1, 6-4 on Friday, dropped the first set by a 6-1 count, but decided he couldn't continue due to a neck injury.

If Nishikori is victorious, he'll become the first player to win consecutive titles here since Tommy Haas in 2006-07.

Sunday's winner stands to take home more than $103,000 in prize money.