Laura Robson once again demonstrated her huge potential as she achieved one of the finest victories of her career by beating world number four Agnieszka Radwanska in straight sets at the Madrid Open.

The 19-year-old had never previously defeated someone inside the top five but a ruthless performance saw her completely dominate her opponent to seal a 6-3 6-1 victory and progress to the third round.

Laura Robson
Laura Robson defeated a player inside the top five for the first time in her career. [Reuters]

Robson has been horribly out of form for much of the season and was knocked out of the Portugal Open in the first round just over one week ago. After struggling in her first round match in Madrid there were few who gave her any chance against Radwanska but the Briton played brilliant from start to finish.

The world number 41 returned superbly throughout the match and secured her first break of serve in the eighth game of the first set to take a 5-3 lead.

Robson held her nerve to clinch the first set and immediately stepped up another level to produce some scintillating tennis.

Radwanska, the 2012 Wimbledon finalist, had no answer and was broken on four occasions in the second set as she suffered defeat in just one hour and 13 minutes.

"I'm really happy with how I played today and I went on the court with a clear game plan," Robson told BBC Radio 5 live. "I've practised with her a couple of times so I knew what her strengths and weaknesses were.

"I'm happy with my returns and a lot happier with my serves as well. It's definitely great to beat a top 10 player, especially on clay. It's a very exciting day for me."

Robson has suffered six first round defeats this year but will be hoping that she can find some form on clay as the French Open begins in less than two weeks.

The British number one will next face either Ana Ivanovic or qualifier Chanelle Scheepers who meet in the second round later today.