UPSET ALERT! World No 2 suffers shock defeat in Miami Open quarter-finals

World number two Aryna Sabalenka suffered a shock straight sets Miami Open quarter-final loss to resurgent Romanian Sorana Cirstea, who reached her first WTA 1000 semi-final in a decade.

Cirstea, ranked 74th in the world, triumphed 6-4, 6-4 against the Australian Open champion to secure her first WTA 1000 semi-final since Toronto in 2013.

The 32-year-old is enjoying an upturn in form since taking on Swede Thomas Johansson as her coach, reaching the quarter-finals at Indian Wells and beating world number four Caroline Garcia of France in both legs of the "Sunshine Swing."

Sorana's MOMENT ??@sorana_cirstea stuns No.2 seed Sabalenka to reach her second WTA 1000 semifinal! #MiamiOpen pic.twitter.com/tH6njQAQKv

In her first meeting with the big-serving Belarusian, Cirstea looked comfortable and composed as she broke Sabalenka's first service game.

The 24-year-old from Minsk, who is now based in Miami, broke back to make it 4-4 but Cirstea swiftly got back in front and held to win take the opening set with her opponent looking visibly irritated and frustrated as she laboured in the early afternoon heat and humidity.

Again, Cirstea broke on her opponent's first serve game and then at 5-4 up, she survived two break points before a superb ace down the middle gave her match point, which she converted when Sabalenka went long.

The veteran reacted with a broad smile and a fist pump and conceded she was surprised by the victory.

"I am a bit speechless," she said. "I came out hoping that it would be a really tough match. I tried to hold my ground. I'm very happy with my performance today, it is a bit unexpected to be honest."

"I had confidence in my game. I knew I was playing well, and I knew that if I come out swinging and being aggressive,