Not too long until Serena Williams takes to the court to face Simona Halep. While we await the entrance of the players, here’s a look at why Serena is surprising a few people at this year’s US Open.

WILLIAMS 6-2 4-6 6-3 HALEP: GAME, SET, MATCH! A forehand winner finds the line to open proceedings before a big serve up the tee moves Williams to within two points of the semi-final. A backhand winner gives Williams three match points but a stunning backhand winner even stuns the great woman herself. No matter, though, as Halep then hits long and Serena is in another US Open semi-final.

WILLIAMS 6-2 4-6 5-3 HALEP: Halep races to one of her easiest love holds of the night. Now she must break, though…

Sun setting on Halep's US Open?

WILLIAMS 6-2 4-6 5-2 HALEP: Pressure? What pressure. It’s an impressive and nerveless hold from Williams, who closes to within a game of the match with a love hold.

WILLIAMS 6-2 4-6 4-2 HALEP: BIG HOLD. A must win game for Halep and a Williams lob on the stretch puts her ahead before the American hooks a forehand wide. Serena hots long and a Halep forehand winner gives her hope in the set.

WILLIAMS 6-2 4-6 4-1 HALEP: Has Williams broken the Halep resolve? She races to 40-0 before closing it out to 15.

WILLIAMS 6-2 4-6 3-1 HALEP: BREAK! Halep opens with a good serve that produces an easy forehand put away but then hits wide. Another errant forehand puts Williams ahead in the game and a heavy backhand then brings two break points. A big forehand gets the job done on the first and that could be the turning point…

WILLIAMS 6-2 4-6 2-1 HALEP: Halep wins a lovely net exchange and clenches her fist like she now really believes she can do this. But breaking the Williams resolve and spirit is a tough thing to do and the American holds to 15 with some big hitting.

WILLIAMS 6-2 4-6 1-1 HALEP: A first ace for Halep and only her 11th in the tournament edges her ahead before Williams nets. Successive double faults undoes all the good work before Williams hits long and Halep holds a scrappy game.

WILLIAMS 6-2 4-6 1-0 HALEP: Williams in trouble early on at 0-30. An ace pulls her back into it but a forehand winner gives Halep two more break points. Another big serve and an unforced Halep error gets Williams back to deuce and despite leaving a ball that drops in, she closes out a tough opening service hold with a lovely backhand drop volley.

Even Serena’s own coach feared this might happen…

WILLIAMS 6-2 4-6 HALEP: SET! A massive game that sees set points and break points come and go in a game lasting over eleven minutes. Finally Halep, on her fifth set point, gets the job done! Brilliant stuff.

Halep is a game away from the second set...

WILLIAMS 6-2 4-5 HALEP: A great game from Halep forces set point but she dumps a makeable backhand into the net, much to her frustration. Yet another ace down the tee gives Williams game point and Halep nets. Still work to do…

WILLIAMS 6-2 3-5 HALEP: A fierce return off a weak second serve gives Williams the early edge but Halep then puts some heat on a forehand to force the American to net. A backhand winner takes Halep to game point at 40-15 and another big forehand forces Williams to net. Only a game away!