No.18 seed Wang Qiang reached the quarterfinals of the Miami Open for the first time in her career with a straight-set victory over compatriot Wang Yafan.

Wang Qiang upset the unseeded Wang Yafan in straight sets 7-5, 6-4, to reach the last eight and advanced to the quarter-finals at a Premier Mandatory event for the second time since China Open last year.

Earlier, Romanian third seed Simona Halep claimed her fourth successive win against Venus Williams with a 6-3 6-3 to reach the quarter-finals. 

"I'm really happy with my game and the numbers back that up," said a delighted Halep.

Wang Qiang will meet with Halep again since Indian Wells quarterfinal loss. 

Chinese Taipei's Hsieh Su-Wei continued a good form following up her defeat of Naomi Osaka to beat former World No.1 Caroline Wozniacki in a three-set thriller and move into the last eight.

The No. 27 seed beat the Danish 6-3 6-7 (0-7) 6-2 and will play Estonia's Anett Kontaveit in the last eight.

Federer through

Roger Federer remains on course for the 101st title of his career after Serbian Filip Krajinovic was dispatched 7-5 6-3 on Monday.

The Swiss superstar produced an excellent all-round performance despite being tested by the world number 103 who belied his lowly ranking by producing some excellent tennis during an exciting first set.

"It was a difficult start, he's a great returner so I knew I had to up my percentages and I served really well," said Federer, who hit 14 aces and won an impressive 74% of points on his first serve.

"It was more humid today so I am just delighted to get through."

(With inputs from AFP)