Memphis, TN (SportsNetwork.com) - Kei Nishikori defeated Croatian challenger Ivo Karlovic on Sunday to win the U.S. National Indoor Championships tennis event for a second straight year.

The top-seeded Nishikori needed just 90 minutes to take out Karlovic in a 6-4, 7-6 (7-0) victory.

Nishikori became the first player to win consecutive titles here since Tommy Haas in 2006-07 and won the fourth title of his career.

Karlovic failed in his bid for a sixth title and first since Bogota last year.

Nishikori took home $103,100 in prize money for the victory.