Victoria Azarenka v Serena Williams in US Open final as it happened

Williams, eyes glistening with determination and a fervent crowd encouraging her over the finishing line, taps her racquet strings in recognition of a breathtaking croscourt backhand winner from Azarenka for 15-30. Silence as Williams prepares to serve... Azarenka finds the tape once again and looks up towards the dark New York sky in despair. Is she seeing her US Open title hopes fade into the distance I wonder. Another forehand return into the net and Williams has her nose in front. Don't go to bed yet.

All Azarenka has to do is hold serve. Hold serve in front of 23,000 fans in the biggest tennis arena in the world. Williams has Azarenka on the defensive and the world number one can only find the tape with a backhand for 0-30... Cripes. Triple break points Williams! A whipping forehand winner down the line reduces the deficit but Azarenka directs a forehand into the net and we're all square! Even stevens! Level-pegging! Describe it how you like. Incredible.

The clock ticks past the two-hour mark. Does the Williams comeback begin here? Williams plops a looping backhand into the tramlines - her 44th unforced error of the match - for 30-30. Venus is biting her fingernails... Williams holds on to fight for another game though as that backhand of hers becomes a lethal weapon once again. A winner down the line and the crowd are whipped into a frenzy.

The crowd cheer wildly as Serena moves 15-30 ahead. Oh my. Utter discontent from Azarenka as she nets to present Williams with a break point. "Come on" she yells to herself as Williams loses her balance after an Azarenka forehand kicks up off the paint. Deuce. Venus is captured shouting words of encouragement to her little sister after Azarenka ups the ante and the pride of Belarus moves to within a game of the title thanks to a walloping forehand winner down the line.

The Williams serve malfunctioning and, quick as a flash, it's 0-30 Azarenka. First serve misses the target... nerves jangle... the second serve is good, but Williams directs a backhand into the net to award three break points to Azarenka. Some spectators demand hush. The majority listen. Williams sends a forehand long and a clinical Azarenka gobbles up her chance, breaking her opponent to love.

Azarenka, hoping to become only the second woman to win the US Open junior title and the women's singles title, is keeping Williams on her heels and forcing her towards the back of the court. Williams directs a couple of forehands long and then pushes a reply into the net - and it's a comfortable hold for the world numero uno.

A fourth double fault of the match from Williams edges Azarenka ahead at 0-15, but more often than not Williams's serve is a friend rather than a foe and two aces - the second a 123mph boomer - helps nudge Williams out in front again. The fat lady has no idea when she'll be asked to start warbling.

Serena's mum glances up at the scoreboard and probably doesn't like what she's seeing. Her daughter is 40-15 behind and facing an uphill struggle to win her fourth US Open title. But hang on. Williams finds the corners with two pin-point backhands for deuce. Azarenka sends her opponent lunging from tramline to tramline, the ball loops into the air and silence descents upon Ashe as the crowd nervously watch Azareka's overhead volley graze the paint. Another defensive lob from Williams and this time it works in her favour. A nonchalant forehand return for break point... and she grabs it with a driving forehand winner!

Williams has not lost in three previous Grand Slam finals against world number ones. She beat Martina Hingis in New York in 1999, defeated her sister Venus at Wimbledon in 2002 and Lindsey Davenport at the Australian Open in 2005. She's teetering here, though, as Azarenka ratchets two break points. A 125mph ace saves one, but Williams drags a backhand into the tramlines to hand the initiative to the Australian Open champ.

Azarenka, wearing the radioactive yellow top with matching sweat bands and shoelaces which have been her uniform throughout the fortnight, doesn't start with the vim and verge of her outfit as Williams scoots to the net and clenches her fist when she pushes a volley beyond her flat-footed rival. Azarenka, under pressure, directs a forehand long for break point, but Williams lets her off the hook with a careless return. Williams sees Azarenka is off balance and dashes to the net to unleash a driving volley for her second break point - and ninth of the match. Danger averted and Azarenka sends Williams hither and tither before finishing off the game with a cute overhead volley. It's been 17 years since a women's final at Flushing Meadows went to three sets but, boy, is this worth the wait.

Here we go then. Cowboy-style whoops and hollers from the enthusiastic spectators as Williams takes her place on the baseline. Uneasy shuffles from the Williams camp, though, as their lady double faults for 0-30, but Williams wriggles free and concludes the opening game with a lethal ace. Wow.

Return these beauties if you can, says Williams. Ace - a seventh of the match. Ace - her eighth of the match. Bish and bosh. And it's an easy peasy lemon squeezy hold for the 30-year-old. Not a glimmer of a smile from the three-time US Open champion though as she strides back to her chair.

Everything seemed to be going Williams's way in the first set, but now driving volleys are plonking into the tape and her groundstrokes are failing to hit the target. The Olympic champion does conjure a delicious return down the line for 30-30, but fails to prevent Azarenka from edging ever closer to levelling this magical match.

Shot du jour! A sliding forehand winner down the line from Azarenka receives raucous cheers from the New York crowd. Azarenka steps in from the baseline and Williams must have noticed the Belarusian's movement from the corner of her eye as the pressure tells and she double faults for two break points. An Azarenka return bounces long and it's a wild "come on" from Williams as we're at deuce. Third break point Azarenka, which Williams negates with a classy ace. Oh to have such a wonderful serve to call upon. Williams's groundstrokes are proving to be her downfall, though, as a haphazard backhand return gifts Azarenka a fourth break point and the top seed has to do little to grab her chance as a Williams forehand sails long. The Wimbledon champion whacks her racquet in disgust. Ouch.

Azarenka, of course, is competing in only her second Grand Slam final, and her first at Flushing Meadows, so her nervy start was perhaps understandable. The Belarusian puts her hands on her hips and shakes her head in disbelief as she produces a double fault to gift Williams a break point with sparklers and hundreds of thousands on top. The Williams forehand not quite on song and the opportunity is snatched from her grasp and the top seeds comes out on top of a baseline brawl, with replays confirming her backhand tickled the paint.

Williams cruises to 40-0, but is pulled back to 40-30. Fear not Williams fans, she ends the game with an ace and strides purposefully back to her chair, deliberately glancing in the direction of a line judge to indicate her unhappiness at a foot fault call in the middle of that game.

The Belarusian is shrieking like a fire alarm - and alarm bells must be ringing in Williams's head as she has managed just one point in this set. She lashes wildly at a return and Azarenka holds to love. Ladies and gentlemen, I think we have a tennis contest on our hands.

Ever tried climbing all 101 floors of the Empire State Building, walk across Brooklyn Bridge and run around Central Park on the same day? Azarenka has to achieve the tennis equivalent of that today, you sense. She makes it halfway up the Empire State, mustering two break points - and she's atop of the building jumping like Rocky as Serena double faults.

Thunderous applause ripples around a jam-packed Arthur Ashe Stadium as Williams demonstrates she has the agility of a gymnast as well as the power of a heavyweight boxer. Her title rival is unable to prevent Williams from unleashing winner after winner and another game goes the American's way when Azarenka can only direct a return beyond the baseline.

The camera finds sister Venus sucking on a sugary sweet. No emotion from the five-time Wimbledon champion as she watches little sis pepper the court with a couple of crackerjack winners. A High-pitch wail from Williams, though, as she scampers to the net only to send a volley long and wide and gift wrap a relatively straight-forward hold to the world number one.

Since returning from a serious illness in 2011, Williams has won all five of her meetings with Azarenka. It would take a brave man to bet against the 14-time Grand Slam champion on this form. Azarenka drags her opponent to deuce only to ruin her good work with a meek forehand into the net and Williams greets a booming forehand winner with a stentorian "come on" as she secures a commanding lead after merely 21 minutes.

Azarenka races ahead to 30-0 and moves to 40-15 when Williams fails to get a return over the tape. The Wimbledon and Olympic champion isn't returning the Azarenka serve with such ease anymore and pushes a reply wide to present her opponent with a comfortable hold.

Just 10 minutes have elapsed in the match but already Azarenka looks as if she has a mountain to climb. Williams's serve looks impenetrable and the 30-year-old holds to 15. How can the Belarusian stem the tide? Just be grateful you're not in her shoes, although having said that she is in New York and is the world's finest female player - and she's competing in a Grand Slam final.