NORCROSS, Ga. (AP) — John Isner says he'll need to be well-rested to beat Gilles Muller in the semifinals of the Atlanta Tennis Championships.
Isner took the right path to saving his energy.
Isner overwhelmed Yen-Hsun Lu 6-1, 6-2 in less than an hour on Friday.
The 6-foot-9 Isner, who needed almost three hours to beat James Blake in three tough sets on Wednesday night, faced little resistance from 5-foot-11 Lu, Taiwan's top-seeded player. Isner, the tournament's No. 3 seed, won in 56 minutes, earning quick relief from the Atlanta heat.
"It's good to get off the court quickly," Isner said. "It's what I didn't do my first round, so I'll definitely be fresh tomorrow."
Muller, from Luxembourg, upset No. 2 seed Kevin Anderson of South Africa 7-6 (3), 7-6 (3) in Friday's first match. Muller advanced to his first ATP semifinal since 2005.
Similar to Isner, the 6-foot-4 Muller features a strong serve. He had 14 aces in the win over Anderson.
Isner had eight aces against Lu while winning 29 of 33 first-serve points.
Isner beat Muller in a second-round match in Atlanta last year, but it wasn't easy. Isner had to rally to win 4-6, 7-6 (6), 7-6 (7).
"I remember that match was so tough and I was really fortunate to win," Isner said. "He served well. He's really tough to break, just like I am. Really, it could come down to just a point here or there. It's a chance we could play a tiebreak or two as well."
Top seed Mardy Fish advanced to the semifinals by beating Somdev Devvarman of India 6-4, 6-3. Devvarman, a former two-time NCAA singles champion at Virginia, trailed 5-0 in the second set before winning three straight games.
With dark clouds looming, Fish said he faltered late when rushing to complete the match.
"Obviously those things were pretty ominous," Fish said of the clouds. "I just rushed myself a little bit there. … It got a little hairy there. I was lucky to get off."
Ryan Harrison and Rajeev Ram were to play in the last quarterfinal, with the winner playing Fish on Saturday.
Germany's Matthias Bachinger and Frank Moser beat Drake Bernstein and Kevin King 7-6 (8), 6-1 in Friday's only doubles match.