Justine Henin began her title defense at the Sony Ericsson Championships with a 6-1, 7-6 (4) victory against Anna Chakvetadze on Tuesday.
The top-ranked Henin cruised through the first set then rallied to take the tiebreaker over the seventh-ranked Russian -- making her first appearance at the WTA Tour's season-ending championships -- in the first match of round-robin play in the yellow group.
"The first match and the final I won [here] last year are very different. But I feel very comfortable here," Henin said. "Being here this week is really motivating and I'm very happy. It reminds me of many things but I try to live in the present because it is absolutely different from last year."
Maria Sharapova returned from a near three-week absence to beat Daniela Hantuchova 6-4, 7-5 in the red group. It was the sixth-ranked Russian's first win since Aug. 31.
Sharapova broke her ninth-ranked opponent in the ninth game before holding serve to take the first set.
She then held off a late rally in the second and converted her fifth match point to secure her sixth straight win against Hantuchova.
"I think I did a good job just being positive, being tough and not letting [wasted match points] bother you because that can easily be done and things can start going another way very fast," said Sharapova, the 2004 champion.
Meanwhile second-ranked Svetlana Kuznetsova continued to struggle at the championships and against Ana Ivanovic, who won her third straight over the second-ranked Russian 6-1, 4-6, 7-5 in the other red group match.
Henin, who trailed 2-0 to start the second set, hit a backhander to the corner to take a 4-3 lead in the tiebreaker before serving out for the win, her 21st straight.
Chakvetadze, who withdrew from Quebec City last week with a right shoulder injury, looked out of form with 30 unforced errors and Henin broke twice to take the first set.
Chakvetadze improved in the second and Henin double-faulted to give her an early break in a back-and-forth set.
Both players had trouble with the other's strong ground strokes and Henin, the French and US Open champion, rallied with consecutive breaks to tie it at 3-3.
After trading breaks again to reach the tiebreaker, Chakvetadze hit into the net on the first match point as Henin improved to 3-0 against her.
Sharapova has been hampered by a shoulder injury since the US Open, and had not played since losing to Belarus' Victoria Azarenka in the third round at Moscow.
"It's so great to be on the court and to be able to concentrate on the match and not to worry about my shoulder or anything, just to play," Sharapova said. "I'm not surprised because I was training quite well."
Hantuchova started the second set best, getting a break in the first game. But Sharapova broke back immediately with a crosscourt winner from the baseline to take command.
Ivanovic, celebrating her 20th birthday, dominated Kuznetsova with a break to start to take the first set quickly.
The fourth-ranked Ivanovic, who knocked Kuznetsova out of the French Open on her march to the final, looked set to pull away again in the second set leading 3-0.
But Kuznetsova's forehand came alive as she battled back to 3-3 before breaking for her first lead.
Kuznetsova saved a break chance with an ace in the eighth game and held to force a third set.
But errors returned to undo Kuznetsova in the last set, the Russian hitting a forehand long as Ivanovic led 2-0.