*Venus Williams reached the Wimbledon quarterfinals this morning, but not without some controversy.

The five-time champion arrived on court nearly 10 minutes late for her match against 92nd-ranked Jarmila Groth of Australia. As Groth and the chair umpire waited at the net, Williams didn’t arrive until 12:09 local time for the scheduled noon match.

Saying nothing, Williams simply walked to her chair amid a chorus of boos and just a smattering of applause. Then after only three games, she left the court for a restroom break.

Commemtators theorized that Williams may have been trying to needle officials for placing her match on the smaller Court 2 instead of Centre Court.

After the match, Williams told reporters that she was simply waiting in the locker room for security to come and escort her onto the court, as is the proper procedure. When the clock read 12:05 and security was nowhere to be found, Williams said she decided to just walk on out by herself.

Once the match started, Williams broke back twice to stay in the second set, then escaped in the tiebreaker to beat Groth 6-4, 7-6 (5). The victory sends Williams into her 31st Grand Slam quarterfinal and improved her record to 12-0 in fourth round matches at the All England Club. She remains on track to meet sister Serena, the defending champion and three-time winner, in Saturday’s final.

About an hour after Venus’s match, Serena beat Maria Sharapova 7-6(9), 6-4 on Centre Court .  Tomorrow’s last eight will pit Serena (1) against Li Na (9), Kvitova against Kanepi (Q), Venus (2) against Pironkova and Zvonareva (21) versus Clijsters (8).