Garbine Muguruza has claimed that she is pleased with her Australian Open campaign after being knocked out by top seed Serena Williams in the fourth round.

The Spaniard dominated the match for long spells and won the opening set, but she was unable to hold off the Williams comeback on a day when she felt her improving form was clear.

"Well, right now I'm just sad because I lost," Muguruza told reporters. "Obviously I saw opportunities to win this match, but I'm really happy.

"I lost with the one I had to lose, to say one way. I can say, OK, I lost to Serena. OK, I did a good tournament. I improved a lot. Today I saw my improvements from the pre-season in the match, so I'm happy."

Williams will now meet Dominika Cibulkova in the quarter-finals.