Garbine Muguruza celebrated her birthday in style by beating Mirjana Lucic-Baroni to reach the quarter-finals of the China Open and qualify for the WTA Finals.

Muguruza shot to prominence by reaching her first grand slam final at Wimbledon in July, where she was beaten by Serena Williams, and the rising star has since surged up to number five in the world.

Spaniard Muguruza turned 22 on Thursday and gave herself the great present of a place in the season-ending showpiece in Singapore as well as a last-eight spot in Beijing by ousting Lucic-Baroni 1-6 6-2 6-1.

Muguruza becomes the first Spaniard since Arantxa Sanchez-Vicario played in the WTA Finals in 2001 to compete in the event following a victory in which she won six of the eight break points she earned.

She said: "I was so concentrated during the match - I really had all types of emotions. I wanted to win bad and it was tough. I'm really happy. Was a great gift!

"I'm pretty motivated to continue here and achieve another great result in Beijing. Right now I'm just very happy to be able to be one of the eight players this year. I think it's one of the goals in tennis. There are bigger goals, but it's a really big one."

US Open champion Flavia Pennetta suffered a setback in her attempt to qualify for the WTA Finals when she was surprisingly knocked out in the third round in the Chinese capital by Anastasia Pavlyuchenkova.

The third seed from Italy, playing her first tournament since winning a maiden grand slam title at Flushing Meadows last month, was beaten 3-6 6-4 6-3 by the unseeded Pavlyuchenkova.

Pennetta is due to retire at the end of the season and still has work to do to ensure she will feature in the WTA Finals, as she is seventh in the rankings.

World number 32 Pavlyuchenkova claimed four breaks to Pennetta's three to battle back and set up a quarter-final against eighth seed Ana Ivanovic, a winner against Svetlana Kuznetsova in three sets.

US Open runner-up Roberta Vinci also crashed out with a shock 6-1 3-6 6-1 defeat to qualifier Bethanie Mattek-Sands, who will now face Muguruza.