James Duckworth's title bid at the San Diego Open is over with the Australian eliminated by No.3 seed Marcos Giron.
Duckworth put up a brave fight but was overpowered by the American, going down 7-6 (7-5) 6-3 at Barnes Stadium.
Giron was dominant in the big points, converting all three of his break-point chances, while Duckworth took advantage of just two of his eight opportunities.
Duckworth's demise leaves Chris O'Connell as the last remaining Australian in the draw.
O'Connell plays No.2 seed Jenson Brooksby for a place in the semi-finals.
Giron will now meet British No.2 Dan Evans, who survived an injury scare to defeat veteran Frenchman Constant Lestienne 6-1 6-3.
Having been given a bye in the first round as the tournament's top seed, Evans built momentum with a straight-sets win over Japan's Taro Daniel.
Evans, ranked 25th in the world, broke Lestienne in the third game of the opening set before holding to move 3-1 ahead.
The 30-year-old Frenchman lost his next service game, after which Evans needed a medical time out for some treatment on his arm and leg following a heavy fall.
Evans saved two break points in the sixth game to hold before breaking Lestienne again to take the first set 6-1.
The second set remained on serve until Evans forced another break and then held to move 4-1 ahead.
Lestienne, the world No.76, rallied to break back in the seventh game only to then see his own serve falter again.
After saving four break points, Evans eventually closed out the set 6-3 to complete his victory in just over an hour-and-a-half on court.