Simona Halep returns in her victory over Flavia Pennetta ©Getty Images

World number two Simona Halep gained revenge over Flavia Pennetta with a crushing victory on the opening day of the BNP Paribas Women's Tennis Association (WTA) Finals in Singapore today.

The 24-year-old Romanian was knocked-out of August's US Open in the semi-finals by Italian Pennetta, who went on to claim her first grand slam title, but it was one-way traffic in the first singles match of the end-of-season tournament.

Halep, who is the number one seed due to Serena Williams' decision to skip the event, breezed to a 6-0, 6-3 success against the seventh seed in the Red Group.

"I started the match really well," said Halep, last year's runner-up, after her victory on the indoor hard court at the Singapore Indoor Stadium.

"I played my best in the first set, fast, smart and aggressive.

"I was really enjoying the match today.

Maria Sharapova reacts after coming from behind to beat Agnieszka Radwańska
Maria Sharapova reacts after coming from behind to beat Agnieszka Radwańska ©Getty Images

"I was really happy to be back here.

"It became a tough match, though.

"Every match here is like the final of a grand slam - I played the semi-finals with Flavia in the US Open.

"I knew she'd play better and the second set was much tougher."

Pennetta is due to retire after the 45th edition of the annual tournament, which features the top eight ranked women's players who are then split into two groups of four.

The top two in each will make the semi-finals but the event has lost part of its gloss with the absence of world number one Williams, after the American, who won the last three editions, said she would be taking time to rest after an injury-hit season which nevertheless saw her win three grand slams.

In the second singles match, Russia's five-time grand slam winner Maria Sharapova came from behind to beat 2012 Wimbledon runner-up Agnieszka Radwańska of Poland.

The third seed lost the first set but recovered to win 4-6, 6-3, 6-4 against the number-five ranked Pole in the second Red Group game.

Singles action continues tomorrow with the opening White Group matches, which see Spain's Garbiñe Muguruza play the Czech Republic's Lucie Šafářová and another Czech, Petra Kvitová, face German Angelique Kerber.

In the doubles competition, which also features the top eight pairs, American Bethanie Mattek-Sands and Šafářová, this year's Australian and French Open champions, defeated Spaniards Carla Suárez Navarro and Muguruza 6-3, 7-6.

Czech pair Andrea Hlaváčková and Lucie Hradecká then beat Hungarian Timea Babos and France's Kristina Mladenovic 6-2. 6-1. 

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