GLASGOW, Scotland (AP) James Ward had just won an epic five-set Davis Cup match when he stumbled - almost zig-zagged - across the court and fell into teammate Andy Murray's arms.

For once, Murray wasn't the toast of British tennis.

Raising his game like he always seems to do in the Davis Cup, the 111th-ranked Ward came from two sets down Friday to beat American No.1 John Isner 6-7 (4), 5-7, 6-3, 7-6 (3), 15-13 in 4 hours, 57 minutes. It was the longest U.S. Davis Cup match since the introduction of the tiebreaker in 1989.

The victory put Britain 2-0 ahead and on the cusp of a second straight win over the United States in the first round of the World Group. But the overall score - and Murray's impressive win over Donald Young at the start of the afternoon - was largely forgotten about in the joyous late-evening celebrations inside the Emirates Arena.

When Isner sent a backhand volley into the net on his opponent's sixth match point, Ward threw his racket toward the net, pumped his chest and looked into the air. Then he hugged Britain captain Leon Smith, lapped up the applause of the crowd and made his way wearily over to Murray, who was close to tears.

''Five hours of John Isner isn't easy to do,'' Ward said, referring to one of the most powerful servers in tennis who memorably won an 11-hour match against Nicolas Mahut at Wimbledon in 2010. ''It's pleasing to last longer than he did.''

Ward has won four of his five five-set matches in the Davis Cup.

Head bowed and with a towel around his neck, Isner was applauded off the court by the 7,700-capacity crowd and was emotional even an hour after the match. He has now lost all five of his five-set matches in the Davis Cup, but this one - from two sets up - clearly hurt.

''It's brutal,'' Isner said, his bottom lip quivering and with masses of strapping around his right knee. ''I'm barely going to sleep tonight. It's awful. Mentally, I'm certainly a bit shaken.''

Murray cheered Ward on from the sideline throughout, and looked happier than he did after beating Young.

''Time to remove every item of clothing and run through the streets of Glasgow,'' Murray said on Twitter. ''Absolute farce from James Ward.''

Murray had it much easier Friday, winning 6-1, 6-1, 4-6, 6-2 in his first match in his native Scotland since winning Wimbledon in 2013.

The thunderous reception greeting Murray on his homecoming took him all the way back to the London Olympics in 2012, when he produced some of the best tennis of his career to win gold on the lawns of Wimbledon.

Murray, who was born in Glasgow, fed off the energy with the kind of performance he delivered at the All England Club three years ago. He made only one unforced error in the first two sets against Young, and dropped just five points in seven service games in that period.

''I played an extremely high level of tennis in the first two sets and it was tough to keep that intensity up,'' Murray said. ''I had a lull in the third set and he managed to settle.''

The 47th-ranked Young found his range with his forehand in the third set and broke Murray - for the only time - in the final game. Murray, though, quelled the American's comeback with a composed fourth set and a sliced-volley winner on his first match point was greeted with repeated fist pumps.

Britain is on course to beat the U.S. team for the second straight year at this stage in the World Group, after winning in San Diego in February 2014. Ward beat Sam Querrey in five sets in that series.

The British would clinch the match on Saturday if it wins the doubles, where Jamie Murray - Andy's older brother - and Dominic Inglot are scheduled to face Bob and Mike Bryan. Captains have until an hour before the match to make any changes, but Smith is likely to resist the temptation to play Andy Murray after Ward's win.

''History is not kind to teams who go down 2-0,'' U.S. captain Jim Courier said. ''We have to go to battle and bring it.''