Teenager Ryan Harrison will get a semifinal shot at top-seeded Mardy Fish for the second straight week after both advanced on Friday in the ATP Los Angeles hardcourt tournament.
Harrison, the 19-year-old who reached his first career semifinal in Atlanta last week, showed that was no fluke as he rallied to beat Taiwan's Lu Yen-Hsun 3-6, 6-3, 6-4.
Fish advanced with a 6-2, 6-4 victory over eighth-seeded Russian Igor Kunitsyn.
"It was a little awkward," world number nine Fish said of a match that started with five straight breaks of serve. "Luckily I was able to maintain the advantage, get a hold and get in front."
Fish went up a break in the fifth game of the second set and maintained the advantage the rest of the way.
Harrison played the first ATP semifinal of his career last week in Atlanta, falling to world number nine Fish who went on to capture his second straight Atlanta crown.
"Obviously Mardy's been playing fantastic," Harrison said. "He's in the top 10 in the world. I had a tough one against him last week.
"I'd love to have another shot at him," Harrison said, adding that last week's defeat had given him a few ideas for adjustments that might help him challenge Fish.
Lu, 27, has been building momentum of late after a disappointing 0-6 start to the season.
He defeated third-seeded Cypriot Marcos Baghdatis to reach the quarter-finals here and gained the advantage against Harrison when he broke for a 5-3 lead then served out the first set.
After an early exchange of breaks in the second set, Lu wasted a bevy of break chances in the seventh game as Harrison held serve.
In the next game Lu double-faulted on break point to hand Harrison a 5-3 lead and the American coolly closed out the set with an ace on set point.
"I had a lot of chances," Lu said. "But I didn't play well enough on the key points."
After letting the seventh game of the second set get away from him, Lu said, "I started to sink a little bit."
Harrison got the break he needed in the seventh game of the third set and wrapped it up with a service winner on his second match point.
Friday's other quarterfinals pitted second-seeded Juan Martin del Potro of Argentina against Latvia's Ernests Gulbis and fourth-seeded Brazilian Thomaz Bellucci against American Alex Bogomolov.
Del Potro, winner of the 2008 Los Angeles title, has won both his prior encounters with Gulbis.
The Argentine player has been on the rise since returning from the wrist injury that sidelined him for much of 2010. The layoff saw the 2009 US Open champion fall out of the top 400 in the world, and he has climbed back to 19th.
Gulbis, owner of one career title, has been going in the opposite direction. Having risen to 21st in the world in February, he has fallen to 84th.
Bellucci, 23, is trying to reach his first semi-final since the Madrid Masters in May, where he lost to red-hot Novak Djokovic.