Miami, FL - 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 Pliskova.

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 South Florida in 1998, 1999 and 2001 and was the 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. The 2014 French Open runner-up Halep has won her last 13 matches on tour, which includes a title at Indian Wells two weeks ago.

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."