Querrey, Blake advance in Memphis
Sam Querrey beat Alejandro Falla for the second time in less than a week, defeating the Colombian 6-3, 6-3 in a first round match at the US National Indoor Championships in Memphis, Tennessee, on Tuesday.
Querrey, who won the Memphis title three years ago, hammered six aces and won 74 per cent of his first-serve points as he needed just 58 minutes to eliminate Falla.
Fourth seed Querrey also beat Falla in the quarterfinals of the San Jose tournament on Friday.
Querrey, who is the No 2 ranked American on the ATP Tour, advances to the second round where he will face the winner of a match between Japan's Go Soeda and Marinko Matosevic of Australia.
Defending champion Jurgen Melzer crashed out of the joint ATP and WTA tournament, losing his opening-round match in straight sets at The Racquet Club of Memphis.
The left-handed Austrian lost to Dutchman Igor Sijsling 6-4, 7-6 (7/3).
Sijsling advanced to a second-round match against Croatian top seed Marin Cilic.
Melzer, who was playing with a broken toe, defeated Milos Raonic in last year's final, snapping the Canadian's win streak at nine straight matches.
Japanese fifth seed Kei Nishikori cruised past Ilya Marchenko 6-4, 7-5, while American veteran James Blake defeated German Florian Mayer 4-6, 6-3, 6-2.
Denis Istomin, meanwhile, took advantage of a sluggish John Isner to eliminate the third-seeded American 6-4, 6-3.
Isner struggled through a number of unforced errors and at least a handful of double faults. Istomin of Uzbekistan, ranked 63rd in the world, broke Isner in the seventh game of the first set as Isner hit two shots into the net and sailed a backhand long in the game.
After gaining another break in the fifth game of the second set, Istomin won the set at love on Isner's serve, game point coming on a cross-court passing shot with Isner at the net.
The victory was Istomin's first win over a top-20 opponent since he defeated Fernando Verdasco of Spain, then ranked 18th, in the London Olympics last year.
"I know it's going to be a difficult match for me, and I need to concentrate and take each chance I had," Istomin said. "I did this. I did good. I broke him in the first set, and then I started to feel better on the returns, and I started to read where he served."