Andy Roddick, John Isner advance
Roddick moved on after an ill Philipp Kohlschreiber of Germany retired in the second set. Kohlschreiber stopped while trailing 6-3, 2-1 after missing an easy overhead, shanking a forehand wide and double-faulting to drop his serve.
Isner fought off five match points in the two tiebreakers to defeat Polish qualifier Lukasz Kubot 4-6, 7-6 (9), 7-6 (7). Isner served 24 aces, but failed to break Kubot.
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Next up for the 20th-ranked Isner is Roger Federer, who received a bye in the first round.
Roddick is looking to avoid falling out of the year-end top 10 for the first time in nine seasons. The 11th-ranked Roddick reached the Japan quarterfinals last week, his first tournament since an early exit at the U.S. Open.
"I thought I hit the ball well in what we did play today," Roddick said. "I started to hit the ball pretty well last week, also. I don't feel like I'm fighting myself out there. After the Open, I was able to train the way I want to for the first time in a while."
Roddick will face Guillermo Garcia-Lopez of Spain.
"I felt quite weak so I was trying to play a little more aggressively, play really risky shots just to try to hang in there," Berdych said. "I was really lucky. I don't know what could have happened if I lost the second set."
Chinese wild card Yan Bai, ranked 465th, upset 30th-ranked Radek Stepanek of the Czech Republic 6-3, 6-4 for his first win on the main tour.
Yan will meet fourth-seeded Andy Murray.
"I have some pressure, of course, because this is my home country," Yan said. "[Murray] is a very talented player -- much better than me. I hope to learn from him in our match."
Janko Tipsarevic stopped Andrey Golubev 6-3, 6-4, and Daniel Gimeno-Traver, a lucky loser who replaced the injured Mardy Fish, rallied past Denis Istomin 3-6, 6-3, 6-3 before rain shortened the schedule.
Copyright 2010 by The Associated Press