Miami, FL (SportsNetwork.com) - Three-time champion Venus Williams upset fellow former world No. 1 Caroline Wozniacki on Monday at the $5.3 million Miami Open.

The fourth-round affair saw the 16th-seeded Williams douse the No. 4 seed Wozniacki in 6-3, 7-6 (7-1) fashion on the hardcourts at Crandon Park.

The 34-year-old Williams is a perfect 7-0 lifetime against the Danish Wozniacki, who has taken only one set off the American in their seven career matchups. The American also topped Wozniacki here in Miami in 2008.

"Caroline plays so well. Our last match went down to the wire, and this one did too," Williams said. "I just went for it, to be honest. I respect her so much that I knew I had to bring my best game."

The seven-time Grand Slam singles titlist Williams titled in South Florida in 1998, 1999 and 2001 and was the 2010 runner-up.

Her quarterfinal opponent will be nifty 12th-seeded Spaniard Carla Suarez Navarro, who upended No. 7 seed Agnieszka Radwanska 5-7, 6-0, 6-4.