Kei Nishikori of Japan successfully defended his title at the U.S. National Indoor Tennis Championships, beating Ivo Karlovic of Croatia 6-4, 7-6 (0) on Sunday. Nishikori won his fourth career title along with the $103,100 winner's check and 250 points on the ATP Tour by making this event at The Racquet Club his first successful title defense. 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). More...