Maria Sakkari has managed a big upset in the Mubadala Silicon Valley Classic quarterfinals as she overcame Venus Williams (2-0 set), who is currently ranked as number three in the world.

The 23-year-old from Greece was calm throughout the game, making very few mistakes and didn’t allow her famed opponent to find any opening that would allow her to reach for the win.

Even when put under extreme pressure, Sakkari managed to keep a cool head through it all and claim a stunning victory.

The game opened up with Venus gaining a 3-0 game lead, courtesy of some cold feet from the Greek player’s part, however after that she began to fight back and eventually claim the first set 6-4.

In the second set, the former world number one really turned her game on, and after Sakkari grabbed a 6-5 game lead, Williams sent it to a tie-break. However it was there that the Greek rising star showed she had the edge over her well-known opponent, as she forced her into some unforced errors, winning the set, and consequently the game rather easily (7-6).

It’s worth noting that Williams finished the game with 43 unforced errors.

Heading into the semi-finals, Sakkari’s next opponent will be Danielle Collins, who is unseeded.

TSITSIPAS KNOCKED OUT IN SEMI-FINALS OF CITI OPEN

Greek tennis had another representative do well this week, as Stefanos Tsitsipas reached the semi-finals of the Citi Open in Washington DC.

There he came face to face with world number three, Alexander Zverev whose experience he was not able to overcome, losing the game rather easily by 2-0 set.

Tsitsipas lost the first set by 6-2 and even though he tried to make a come-back in the second, attempting to send the game to a tie-break, in the end it just wasn’t enough (6-4).

To reach the semis, Tsitsipas had previously beaten world number 11 David Goffin 2-0 (6-3, 6-4), which was also an impressive feat.