Updated

Top-seeded Serena Williams faced some early struggles before defeating Russia's Ekaterina Makarova 7-6 (8), 6-0 in the second round of the Dubai Championships on Tuesday.

Williams has been sidelined with a back injury since losing to Ana Ivanovic in the fourth round of the Australian Open last month.

It took Williams the first set to adjust to the left-handed Makarova's ability to jam many of her shots into the top-ranked American's body.

Williams says "I felt a little rusty, but it was okay. Body is fine. I just had to get my feet moving."

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

Seventh-seeded Simona Halep of Romania retired with a right Achilles injury and fatigue while trailing Alize Cornet of France 6-1, 1-1, in her opening match at the Dubai Championships on Tuesday.

The ninth-ranked Halep, who won the Qatar Open on Sunday, complained of an inflamed Achilles during her run to the Doha title.

"I wanted to try because I like to try to fight for my chance, but here I couldn't," Halep said. "After one set I realized that it is dangerous to continue."

The WTA physiotherapists recommend Halep take 10 days off to heal the injury.

The only game Halep won in the first set was when she broke the 26th-ranked Cornet's serve in the third game.

Halep held serve in the first game of the second set. But after Cornet made it 1-1 the Romanian determined she couldn't play on.

Eighth-seeded Caroline Wozniacki overcame a one-set deficit to outmaneuver Sabine Lisicki of Germany 2-6, 6-3, 6-3 to move into the second round.

Wozniacki, who won this tournament in 2011, started the match leading 2-1 with a service break. The Dane then lost the next six games to trail the 15th-ranked Lisicki 6-2, 1-0.

"I knew she was going to come out hot and just go for her shots, and I felt like I was just a step behind," said Wozniacki, who sports an eight-carat diamond engagement ring from golfer Rory McIloy everywhere she goes except on court. "It was nice to win this one."

After evening the score at one-set all, Wozniacki broke out to 4-1.

"Onwards and upwards, as they say," she said.

Wozniacki will face German qualifier Annika Beck in the second round. Beck defeated Samantha Stosur of Australia 1-6, 6-1, 6-4.

Also, fifth-seeded Jelena Jankovic of Serbia beat qualifier Maryna Zanevska of the Ukraine 6-4, 6-3.

Top-seeded Serena Williams, playing here courtesy of a wild card, faced Ekaterina Makarova of Russia late.