|Venue: Flushing Meadows, New York Dates: 29 August-11 September|
|Coverage: Live commentary on BBC Radio 5 live sports extra plus live text on the big matches on the BBC Sport website and app|
Dan Evans failed to take a match point as he lost a five-set thriller to third seed Stan Wawrinka at the US Open.
Evans, seeking to become the fourth Briton to reach the fourth round, had match point in the fourth set tie-break but Wawrinka saved it and came back to win 4-6 6-3 6-7 (6-8) 7-6 (10-8) 6-2.
Earlier, world number two Andy Murray beat 34-year-old world number 40 Paolo Lorenzi 7-6 (7-4) 5-7 6-2 6-3.
He joined Friday's winners Kyle Edmund and Johanna Konta in the last 16.
The last time Britain had three players in the fourth round of a Grand Slam was when John Lloyd, Anne Hobbs and Jo Durie got to that stage at the 1985 Australian Open.
The last time there were two British men in the fourth round of a major tournament was at Wimbledon in 2002 when Tim Henman and Greg Rusedski did so, while it is 50 years since two made the last 16 of the US Open.
'Heart-breaker' for Evans
Evans' match point arrived in the fourth set tie-break but the Swiss saved it with a volley and then created a set point of his own with a cross-court backhand.
The Briton saved that with a volley, but at 7-7 he failed to finish a smash.
Wawrinka had a second chance to serve out and then a third at 9-8, which he finally converted when Evans sent a forehand wide.
Evans, 26, looked mentally and physically exhausted in the fifth as Wawrinka moved 4-0 clear and the two-time Grand Slam champion served out for victory after four hours and three minutes.
"It's a tough one to take, I'm pretty happy to be part of a match like that but also to come off the court losing is a difficult one," he said.
"It's a bit of a heart-breaker really. Taking a bit of time off now will be good physically and mentally because it was difficult tonight.
"I need to get it out of my mind so a bit of time off will be good."
Evans also said that pulling out of the doubles competition might be "the sensible thing to do", with Great Britain hosting Argentina in the Davis Cup semi-final on 16 September.
The Birmingham player had never made the fourth round of a major tournament before but the world number 64 has enjoyed a remarkable rise, climbing into the top 100 in May, having been ranked 772nd last year.
Wawrinka will next play Illya Marchenko of Ukraine after Australia's Nick Kyrgios retired through injury.
"I am lucky to get through that match, serving against match point," Wawrinka said.
"It was a tough battle. He played really great, he is talented, was pushing me a lot and I feel amazing to come through this."
Analysis - Evans the tormentor
BBC Sport tennis correspondent Russell Fuller
Dan Evans was tantalisingly close to pulling off the shock of the first week. He considers it an opportunity missed - and he did serve a double fault when two points away from victory at 5-4 in the fourth set tie-break - but it was not an opportunity he threw away. Wawrinka was physically and mentally stronger in the fifth set, but until then Evans had tormented the double Grand Slam champion with his use of slice, and often found just the right moment in a rally to land the knockout blow.
Evans later signalled his intention to pull out of the doubles to rest a sore foot - and his partner Nick Kyrgios may not have any complaints after retiring from the singles with a hip injury. After eight weeks on the road, Evans says he needs a few days holiday before the rigours of a Davis Cup semi-final.
I was going for too many shots - Murray
Murray, vying to become just the fourth man to reach all four Grand Slam finals in a calendar year, looked in commanding form in his first two matches but struggled against an inspired Italian opponent.
He made 47 errors in the first two sets before turning the match around with a change of tactics.
"I stopped rushing in the rallies. I was making quite a few unforced errors," said Murray, 29, after finally seeing off Lorenzi after three hours and 17 minutes.
"I was trying to get cheap points, I was going for too much.
"When I slowed things down and waited for the right shot to go for, my unforced errors went down, the winners went up and the scoreboard started working in my favour."
The Olympic champion now faces Bulgarian Grigor Dimitrov in the last 16.
Lorenzi rocks Murray's composure
Lorenzi won his first ATP title in July but had only won two Grand Slam singles matches in 13 years before arriving at Flushing Meadows.
The Italian, who won a five-set marathon over French 30th seed Gilles Simon on Thursday, frustrated Murray with his energy and accuracy.
After losing a first-set tie-break, Lorenzi deservedly won the second with some superb tennis as Murray grew increasingly irritable with his error-strewn performance.
But the 2012 US Open champion pulled himself together, cut out the errors and dominated the third and fourth sets to finally secure victory.
Murray's impressive numbers
- Won 25 out of 26 matches since the beginning of Queen's Club in June
- Made the fourth round of a Grand Slam for the 23rd consecutive tournament he has played
- Has an 18-1 record against Italians since 2008 with his lone loss coming to Fognini in 2014 Davis Cup quarter-final
- Reached seven successive finals since the ATP Masters 1000 Madrid in May
Wildcard Del Potro powers through
Argentina's Juan Martin del Potro reached the fourth round for the first time since 2012 with a 7-6 (7-3) 6-2 6-3 win over Spanish 11th seed David Ferrer.
Del Potro, the 2009 champion but ranked 142 after a series of wrist injuries, will now face Austrian eighth seed Dominic Thiem - who celebrated his 23rd birthday with victory over Pablo Carreno Busta.
"It doesn't matter if I win or lose," said 27-year-old Del Potro. "I just want to play my tennis again after so many problems.
"If I can hit my forehand again like I did in 2009, then it will be fun for everyone."
Kei Nishikori, the sixth seed from Japan and a potential quarter-final opponent for Murray, beat France's Nicolas Mahut 4-6 6-1 6-2 6-2.
He plays 21st-seeded Ivo Karlovic next after the Croat beat 19-year-old American qualifier Jared Donaldson to become the oldest man to reach the fourth round since Jimmy Connors was 39 in 1991.