Lleyton Hewitt eased into the quarter-finals of the Hall of Fame Tennis Championships by thrashing Prakash Amritraj.
The veteran Australian had it all his own way against Indian wildcard, beating him 6-2 6-1.
Ivo Karlovic also won, seeing off Canada's Vasek Popisil in three topsy-turvy sets 6-11-6 6-3 to set up a meeting with defending champion John Isner, who beat Adrian Mannarino 6-0 7-6 (9-7).
"I was tired. I just felt really down fitness-wise because I was out for a long time, so now every match is difficult, but hopefully the ups and downs will be less and less every week," Karlovic told the ATP's official website.
The Croatian, who has been out with April due to meningitis, added: "I really didn't know that I would be back, so now it is a good feeling out there because I feel no stress. I'm not even supposed to be here so it's like a bonus. I just feel good."
Elsewhere, Igor Sijsling needed little time to get the better of Yuichi Sugita.
Michael Russell beat Alex Kuznetsov 6-3 6-4, while American Rajeev Ram went down in three to Michal Przysiezny, who won 2-6 7-5 6-3.