Nick Kyrgios barely raised a sweat as the second seed reached the Atlanta Open quarter-finals, though Frances Tiafoe and Jeremy Chardy were not so fortunate.
Kyrgios needed just 56 minutes to dismantle American qualifier Noah Rubin 7-5 6-2 at the ATP 250 tournament on Thursday.
Champion in 2016, Australian star Kyrgios – seeking his second title of the year after triumphing in Brisbane – hit 15 aces and won 83 per cent of his service points to move through to the last eight.
"I always feel comfortable playing here," Kyrgios said. "Obviously had a fair bit of success here. I just feel comfortable. The court suits my game-style. I can serve well, I can make a couple of returns and play aggressively."
Next up for Kyrgios, who has advanced to the quarters in four of his last five events, is Cameron Norrie.
World number 73 Norrie rallied to upstage sixth seed Chardy 5-7 6-4 6-4.
American fifth seed Frances Tiafoe was stunned 7-5 6-1 by veteran Marcos Baghdatis, who will meet Matthew Ebden after the fourth seed eased past Donald Young 6-4 6-4.
