Miami, FL (SportsNetwork.com) - Resurgent German Andrea Petkovic was an easy quarterfinal victor Tuesday at the $5.3 million Miami Open.

The oft-injured ninth-seeded German star blew past 14th-seeded big-serving Czech Karolina Pliskova 6-4, 6-2 in 75 minutes on the hardcourts at Crandon Park. "Petko" is now 2-1 lifetime versus the rising Pliskova.

"I was playing really well at the start, but I couldn't see the ball on my serve with the sun on one side, and I was struggling," Petkovic said of some first-set troubles. "Karolina started playing really well, too. I was a little lucky at the end of the first set, and then I was playing better and better from there."

Petkovic was also a Miami semifinalist in 2011.

"I can't explain it, but @MiamiOpenTennis is 1 of my favorite places," the German tweeted following Tuesday's win.

This year's Antwerp titlist Petkovic will face 12th-seeded Spaniard Carla Suarez Navarro or 34-year-old 16th-seeded former world No. 1 Venus Williams in the semifinals. The seven-time Grand Slam singles titlist Venus titled here in 1998, 1999 and 2001 and was the Miami runner-up in 2010.

Two more quarterfinals will be held on Wednesday, when current No. 1 superstar Serena Williams takes on 27th-seeded former Wimbledon runner-up Sabine Lisicki and red-hot third-seeded Romanian Simona Halep battles unseeded American Sloane Stephens. Lisicki stunned Serena in a fourth-rounder at Wimbledon two years ago. Last year's French Open runner-up Halep has won her last 13 matches on tour, which includes a title at Indian Wells prior to this Miami fortnight.

The 33-year-old Florida resident Serena is a seven-time Miami champ and two- time runner-up. The reigning Australian and U.S. Open winner beat Li Na in last year's Miami Open finale for a second straight title in "Magic City."