Good evening and welcome to our updates for number 14 seed Marin Cilic's fourth round meeting with Frenchman Gilles Simon on Luis Armstrong court. The Croatian is looking to book his third appearance in the last eight here at the US Open, while 'Gilou' has matched his best ever turnout at Flushing Meadows which he secured back in 2011. He'll be quietly confident after seeing off fourth seed David Ferrer last time out.

GAME, SET AND MATCH! - CILIC 5-7 7-6(3) 6-4 3-6 6-3 SIMON. Cilic books a place in the US Open quarter finals for the third time in his career, serving down an ace and executing a lovely angled volley to take it in an epic four hours and 13 minutes. It's his first win over Simon in five meetings and it was another rollercoaster affair. The Croatian just about edged it overall and will now take on Tomas Berdych or Dominic Thiem in the last eight.

BREAK! - CILIC 5-7 7-6(3) 6-4 3-6 5-3 SIMON. A massive moment. Cilic senses the opening and goes out all guns blazing. He rampages into a 0-30 lead and then notches up double break point. A barrage of big forehands leave Simon on the defensive and he eventually hooks wide to give the Croatian a clear scent of victory. He now serves for the match.

CILIC 5-7 7-6(3) 6-4 3-6 4-3 SIMON. Chila does what's necessary once again, firing down the big serves and shrugging off the dropped points. It's a hold to 30. This is usually the nervy part of a set, but given the circumstances of this war of attrition, it's fair to say that it's been that way since the very start of the fifth.

CILIC 5-7 7-6(3) 6-4 3-6 3-3 SIMON. Cilic battles his way into the game from a seemingly hopeless position to push it to deuce. A rasping shot down the line then drops just out allowing Simon to finally put it to bed with a 15th ace of the match. It's 3-3 and a TB-decider could well be on the cards.

CILIC 5-7 7-6(3) 6-4 3-6 3-2 SIMON. A fourth double fault of the contest is the only blip for Cilic as he canters to another comfortable game. A challenge on a serve called 'out' goes his way and brings it all to an end far too quickly from Simon's point of view.

CILIC 5-7 7-6(3) 6-4 3-6 2-2 SIMON. Gilou responds with a simple enough service game to 15 when Cilic floats a defensive backhand into the alley after a probing forehand down the line from the 26th seed.

CILIC 5-7 7-6(3) 6-4 3-6 2-1 SIMON. If you blinked or yawned you may have missed that! Cilic surges through the points, powering down ace number 20 on his way to an impressive hold.

CILIC 5-7 7-6(3) 6-4 3-6 1-1 SIMON. A rollercoaster game sees Simon race into a 40-15 lead. However, a double fault and some gritty play by Cilic ensure the Croat forces deuce and he goes on to snare a break point with as good a forehand winner down the line as there has been in this match. But Simon digs deeper and pulls off the hold when Cilic fires long.

CILIC 5-7 7-6(3) 6-4 3-6 1-0 SIMON. That was a big opportunity for the Frenchman. The backhand down the line has been a real weapon for him throughout this contest and it serves him well again as he clocks up break point at 30-40. But Cilic roars back and rattles in a 19th ace of the match to secure massive hold.

SET! - CILIC 5-7 7-6(3) 6-4 3-6 SIMON. After three hours and 28 minutes we're heading into a fifth-set decider. Simon makes no mistakes serving it out, notching up triple set point before making it 2-2 on the second one. This is anyone's match from here; so hard to call.

CILIC 5-7 7-6(3) 6-4 3-5 SIMON. Cilic pulls off a pair of big serves to stave off two separate break points before an unfortunate net cord goes against Simon and hands the 14th seed the advantage. The big Croat delivers another blockbusting serve to leave Simon with no hope of steering it back in court. The Frenchman will now serve for the set.

CILIC 5-7 7-6(3) 6-4 2-5 SIMON. A delicate stun volley at the net brings an end to an enthralling rally as Simon steps it up from 0-15 down to rattle off some big serves and move within one game of taking this fourth set.

CILIC 5-7 7-6(3) 6-4 2-4 SIMON. That was ridiculously quick! A perfect game for Cilic who remains just the one break behind. He won't be giving up on this fourth set just yet.

CILIC 5-7 7-6(3) 6-4 1-4 SIMON. Gilou is in no mood to let this slip. He's got his eyes firmly focused on forcing a decider. A 13th ace of the encounter secures an easy hold and consolidates the break.

BREAK! - CILIC 5-7 7-6(3) 6-4 1-3 SIMON. The plot thickens! This pair are no strangers to going the distance and Simon makes it a very realistic possibility by hounding the Cilic serve and making it count from 30-40 when the Croatian could only slap a forehand into the net.

CILIC 5-7 7-6(3) 6-4 1-2 SIMON. The Croatian continues to pose some questions of the Simon serve but the Frenchman is just about coming up with the right answers. The 14th seed pushes his opponent to deuce twice but can't quite snare a break point. Eventually Gilou is able to come through the test when Chila fizzes wide with a crosscourt attempt.

CILIC 5-7 7-6(3) 6-4 1-1 SIMON. Marin enjoys an easy hold to 15 with the only blemish on his copybook coming when a poorly-executed slice was whisked past him by the Frenchman.

CILIC 5-7 7-6(3) 6-4 0-1 SIMON. The 26th seed survives a brief wobble to close out on an error from Cilic after the Croatian had fought back from 40-0 to 40-30.

SET! CILIC 5-7 7-6(3) 6-4 SIMON. Cilic serves out the set to 30, but it wasn't as simple as he would have hoped. Simon pushed him all the way but wasted a chance on a second serve by thumping a return long. We've had two hours and 48 minutes of tennis and Cilic is one set away from his first ever success over Simon in five outings. Can he do it?

BREAK! CILIC 5-7 7-6(3) 5-4 SIMON. What a way to break! A lengthy rally at advantage ends with a disguised lob that leaves Simon shrugging in dismay. He was completely fooled. It's no more than Cilic deserves after hammering at the door for so long. He'll now serve for the set and a 2-1 lead.