I'm not going to lie to you, that was a bit of a grind, at least to watch - there was only ever one winner after Murray came roaring out of the traps and showed Kuznetsov what big guns he's got, but it ended up being a bit more of a slog than it should have been for the eighth seed. That said, he got it done. Anyway, that's me, I bid you farewell.

Andy Murray: "I just tried to stay solid. It was a tough match but I feel better than I did in the first match.

"I made sure I did everything properly. I love it here. I have enjoyed coming here since I was a junior. I play some of my best tennis here."

Image source, Reuters

Miles Maclagan
Former coach to Andy Murray on BBC Radio 5 live Sports Extra

"We had to wait more than two hours for his smile. A great effort, a couple of minor blips but I don't think he will be overly concerned because we have seen it all before. The good news is physically he seemed fine and he will have extra recovery time over others."

Murray moves into a 30-0 lead with a cross-court forehand winner but Kuznetsov proves he has a pulse with a fizzing backhand down the line. Murray finds a biggun down the middle for two match points and wraps things up with a naughty backhand volley. Murray through to the fourth round, where he will meet either ninth seed Jo-Wilfried Tsonga or Pablo Carreno Busta of Spain, who are about to get under way on Grandstand.

Thunderclap forehand return from Murray for 15-30 and a hefty backhand return forces the Russian to net with a backhand of his own. Kuznetsov saves one break point but he can't save the second, finding the net once again. Murray to serve for the spoils...

Well I never, Kuznetsov's will wasn't broken after all and here's a break point... taken, that was a pretty limp service game from the Briton.

Murray moves into a 0-30 lead before Kuznetsov gives himself hope with an ace down the middle. Clunking backhand return by Murray gives him two break points but he can't convert the first, firing long with a forehand. And what a neat winner this is from the Russian, a half-volley on the backhand side on his haunches. Back-to-back double faults from Kuznetsov, his spirit looks broken...

Murray doinks a backhand long after a lengthy baseline battle and it's 0-30. Kuznetsov misses the baseline with a forehand and Murray claws it back to 30-30. The Russian frames a forehand return high and handsome before Murray carves out a lovely point, setting up the killer punch with a sliced backhand before putting away the volley at the net.

Pauline Smith:, external Come on Andy, don't put us through agony!

Rachael Collins:, external Hoping the cramp's not returning, Andy Murray.

Miles Maclagan
Former coach to Andy Murray on BBC Radio 5 live Sports Extra

Image source, Getty Images

"Strong play from Murray. He stuck his chest and asked a question too many of the young Russian. The question now for Murray is will he keep the intensity up to keep his opponent at bay?"

Signs that Murray is turning the screw here, too much on that backhand for his opponent. Kuznetsov finds a big first serve and forehand winner for 30-15 before Murray jumps into a backhand return that leaves the Russian clawing at midair. Here's a break point... Kuznetsov is finally worn down by the garage door on the other side of the court and fires a forehand long, that's a break.

Murray holds his first service game of the fourth set, no great dramas there...

Miles Maclagan
Former coach to Andy Murray on BBC Radio 5 live Sports Extra

"Kuznetsov has settled into things and will be feeling very good about his game. He would be deflated if he lets Andy get a jump start on him in this set."

Well, I didn't think we'd still be here half an hour ago, which doesn't really make any sense thinking about it, but you know what I mean. What about a five-setter? Who knows, with Murray in this kind of quixotic form. But here's a break point to kick off the fourth set, which he is unable to convert. Kuznetsov fires an ace down the middle for the advantage but finds the net with a backhand on the next point. Murray shovels a backhand long before muffing an attempted backhand pass down the line, the Russian holds.

Miles Maclagan
Former coach to Andy Murray on BBC Radio 5 live Sports Extra

"So often Andy Murray leaves us scratching our heads. After getting back into the set and looking so brilliant at 4-4, you thought he would ride it through but produce a string of unforced areas and it doesn't matter who you are playing."

Murray sprays a forehand wide and wanton after a baseline dust-up before plonking a forehand smash miles long to hand his rival two set points. The Russian only needs one of them, Murray has plenty more spade work to do.

Piers Newbery
BBC Sport at Flushing Meadows

"As Murray worked his way back into this third set, his every move was being examined for signs of the dreaded cramp returning. Never the easiest to read in terms of body language, there have been a few indications of discomfort between points. He continues to move well enough when the ball is in play. Maybe time for a few salt sachets from the restaurant."

Image source, Reuters

What a shot that is from Kuznetsov, Murray floating one up from behind the baseline and the Russian standing his ground and putting away the smash from the back of the court. Unlucky Kuznetsov, there's some tension in these nets and a net cord sends a forehand long and out. The Russian finds a good first serve to hold only to hand Murray another break point... this time the net likes Kuznetsov, leaving Murray rooted... and Murray plonks a tame forehand into the net...

Murray scampers into the net and puts away a forehand winner for 40-0, and you sense increased intensity from Murray here. Murray knifes a backhand into the onion bag but his rival also finds the net with an attempted drop-shot to hand him the game.

Meaty hitting from Murray, finished by a crunching backhand winner for 0-30. Kuznetsova is unable to deal with that forehand return by Murray and here's three break-back points... the Scot only needs one of them, we're back on serve...