Serena Williams made a big statement in her opening match of the WTA Championships in Istanbul with a comprehensive 6-4 6-1 victory over Germany's Angelique Kerber.
Williams was playing in her first match after a five-week lay-off following her US Open win in New York when she took her tally of grand slam titles up to 15, and apart from a couple of first set games she looked as good as ever.
Kerber matched the American shot-for-shot early on, with both players grabbing a break of serve, but Williams found top gear towards the end of the first set and the pressure started to tell on Kerber, in what was the toughest match possible for her to make her debut in the event.
The German had game point in the tenth game of the set but double-faulted for the third time and Williams pounced on the error by winning the game, and the set after 45 minutes on court.
Kerber was up against it from then on, and never really got a foothold in the second set with Williams breaking her in the fourth and sixth games to lead 5-1.
The two-time former champion then had to see off two break points as Kerber showed some fighting spirit, but Williams would not be denied as she finished off the contest after an hour and 18 minutes.
Williams has been almost unstoppable this year, losing just four matches, and she now takes charge of the red group in the round-robin portion of the competition in Turkey.
The Wimbledon and Olympic champion will now face Victoria Azarenka and Li Na in the rest of her round robin matches - ties that will also prove no easier for Kerber after such a testing first match in the event.
After the match Williams said she was glad to finally get back in competitive action following her US Open triumph.
"I felt like I practiced too much, and if I hit another practice ball I'm going to go nuts," she told the WTA's official website.
"I just really wanted a match. I was glad I played on the first day. I was like, 'If I have another practice day, I don't know if I can handle it.'"
She added of Kerber: "I could feel she was really excited all week long. She's really happy to be here and feels honored to be here, and she deserves to be here, because she worked hard and has been one of the most consistent players on the tour.
"I think 10 semi-finals is pretty impressive, and winning two titles, as well. I think she will have a lot more chances to play at this event."