Lleyton Hewitt recovered from a set down to see off Carlos Moya in their rain-delayed match in the Masters Cup. Hewitt lost a tight first set on a tie-break but came back well to win 6-7 6-2 6-4 in Houston.
The in-form Marat Safin also made a winning start with a 6-1 6-4 success over Argentina's Guillermo Coria.
Coria, the French Open runner-up, had not played since 27 July when he suffered a shoulder injury in Toronto and later underwent surgery.
Hewitt had led 5-4 against Moya when play was suspended on Monday evening because of rain.
The Spaniard battled hard to take the first set tie-break 7-5 but his exertions seemed to take their toll in the second set and Hewitt regained control.
Moya saved a break point in game one of the third set but Hewitt capitalized on his next chance in the seventh game.
He hit a running forehand winner on the sideline to get a break point and Moya netted a forehand to give Hewitt a 4-3 lead and he never looked back after that.
"I didn't feel like there were too many lapses. I'm pretty happy with how my game was," Hewitt said afterwards.
"I served extremely well. It played a huge part in the match. I was able to dictate play a little bit more and that's one reason I won."
Safin, who has only lost three of his last 26 matches, broke Coria in his first and last service games to claim the first set in only 19 minutes.
He then had an early break in the second set and wrapped up victory in an hour.