Marcos needed one hour and 17 minutes to turn aside qualifier Austin Krajicek 6-4, 6-0 at the BB&T Atlanta Open on Tuesday. It was the second time in consecutive matches he served up a bagel set.
Meeting for the first time, Marcos fired five aces and won 72 per cent of total service points, including 14 of 18 on his second serve. He also saved both break points faced, while converting on four of six of his own.
Marcos has now won seven of his last eight matches against American opponents. Seeded fifth this week, he claimed his 280th match win on the ATP World Tour, improving to 17-12 on the season.
Competing for the first time in Atlanta, Marcos will square off against Australian Sam Groth in Wednesday's second round. The winner will face either second seed Vasek Pospisil or Yen-hsun Lu.
