LOS ANGELES, (Reuters) – China’s Zheng Jie  capitalised on a final set meltdown by world number one Dinara  Safina to reach the quarter-finals of the LA Championships with  a 7-5 4-6 6-4 victory over the Russian on Thursday.

The 14th seeded Zheng stood strong against a barrage of  huge blows from her opponent over the course of the two hour,  10 minute contest to emerge with a first win in five attempts  against the defending champion.

Safina had appeared on course for victory when she forged a  4-2 lead in the third set but imploded completely, handing back  the break with a double fault before losing the final eight  points of the match to crash out of the tournament.

“It’s tough to play her but I didn’t do the right things,”  Safina told reporters. “I should have played better. She took  her chances and beat me.”

Zheng advanced to a last eight encounter against in-form  Australian Samantha Stosur, who continued her fine season with  a 6-3 6-2 victory over sixth seed Ana Ivanovic.

The 13th seed was delighted to overcome the Serbian former  world number one, gaining some revenge for losing to Ivanovic  in their last meeting at Wimbledon in June. It was also  Stosur’s sixth win over a top 15 opponent this year.