LOS ANGELES (AP)—Teenager Ryan Harrison continued his recent run of strong form by beating fellow American Michael Russell 6-3, 6-4 on Wednesday to reach the quarterfinals at the Farmers Classic.

Lu Yen-hsun of Taiwan had the day’s biggest upset, defeating No. 3 seed Marcos Baghdatis of Cyprus 6-3, 6-4 to set up a matchup against Harrison, who is attempting to make consecutive semifinals appearances.

Baghdatis, ranked 30th in the world, was playing his first match after receiving an opening-round bye.

Ernests Gulbis of Latvia had little trouble in defeating qualifier Daniel Kosakowski 6-2, 6-4. Gulbis will play either No. 2 seeded Juan Martin Del Potro or Argentina and American James Blake, who take the court in Wednesday’s late match.