Top seed Simona Halep praised Maria Sharapova for producing a stunning display to nullify her aggressive game at the WTA Finals.

Halep went into Tuesday's clash in Singapore on the back of a comprehensive victory over Flavia Pennetta but was unable to replicate that against the world number four.

Sharapova was quickly on top with a show of powerful baseline hitting, and Halep acknowledged the class of her opponent.

"I think she had a good day today," the Romanian said. "She played her best. She deserved to win and I give her a lot of credit for this match.

"She was moving pretty well. Like I said, when I opened the court she did some unbelievable shots. She didn't miss. She was very close to the line.

"I knew that I stayed too far back, too far away to the court, so I tried just to come more close to the baseline to be more aggressive. But she played well, like I said. She didn't let me play my game."

Defeat means Halep needs to win her final pool match against Agnieszka Radwanska to guarantee progress to the semi-finals, while hoping Pennetta does not beat Sharapova in straight sets.

She added: "I don't want to think about this. I have one more match. If I will be in semi-finals, it's okay. If not, it's the same.

"Of course I want to be in the semi-finals if I can. But first I have to think about the match against Radwanska because it's going to be tough."