World number two Maria Sharapova has expressed her relief at defeating six-time Grand Slam singles winner Venus Williams.

The Russian overcame Williams in straight sets to reach the fourth round of the Australian Open on Friday evening.

Sharapova, who won her first two matches in Melbourne without dropping a single game, had been 6-1 5-1 ahead against Williams, before she eventually prevailed 6-1 6-3.

"When the draw first came out that was the matchup that we were both looking forward to," said Sharapova. "She's always a very tough opponent to play, I was just really determined out there.

"I was up 5-1 then made a few more errors than I would have liked to, so I was really happy to just serve it out."

Sharapova and Williams have now contested 10 matches against each other, winning five apiece.