Narrator Andy Taylor | The Voice of the US Open | Photo: USTA / Darren Carroll
 Juan Martin Del Potro -03- (ARG) def  John Isner -11- (USA) | 67(5) 63 76(4) 62
Two big servers. Quick holds. Thin margins.
Expectedly, the above defined today’s Quarterfinal – up until the 3rd-set tiebreak. Isner took set-1 with a single mini-break. Delpo took set-2 with a single break after the first changeover. Delpo’s two mini-breaks to John’s one determined set-3.
Attrition took hold in the fourth. Isner dropped serve before the first sit-down – then Delpo broke again to claim victory as John dumped an exhausted forehand into the net.
Ultimately, the match came down to unforced errors. John hit 67 winners, compared to Delpo’s 49. However, Isner’s 51 unforced errors completely eclipsed Del Potro’s 14.
The two have played three times this year. John won their first battle in the Miami Semifinals 61 76(2), where he captured his 13th title. Juan Marin won their 4th-Round meeting at Roland Garros 64 64 64. After their 12th career match, Delpo now owns an 8-4 edge over the top-ranked American.
Fans are in for a Semifinal treat. The 2009 US Open Champion gets Rafael Nadal next.
NEXT:  Juan Martin Del Potro -03- (ARG) vs  Rafael Nadal -01- (ESP)
QF: def  John Isner -11- (USA) 67(5) 63 76(4) 62 | Arthur Ashe Stadium
R4: def  Borna Coric -20- (CRO) 64 63 61 | Arthur Ashe Stadium
R3: def  Fernando Verdasco -32- (ESP) 75 76(6) 63 | Arthur Ashe Stadium
R2: def Denis Kudla -72- (USA) 63 61 76(4) | Louis Armstrong Stadium
R1: def Donald Young -246- (USA) 60 63 64 | Louis Armstrong Stadium
 Juan Martin Del Potro -03- (ARG)
9-years-ago he captured his first Grand Slam title right here in Arthur Ashe Stadium, defeating Rafael Nadal in the Semi’s, then 5-time defending champion Roger Federer in a thrilling 5-set Final. He’s a Davis Cup Champion, an Olympic Bronze and Silver Medalist, and with victories this year at Indian Wells and Acapulco – now owns 22 ATP World Tour Singles titles. He’s reached 4 Finals this year alone – and comes into this year’s US Open with a career-high ranking of world #3. A Semifinalist here last year – From Argentina, please welcome 2009 US Open Champion…Juan Martin Del Potro.
 John Isner -11- (USA)
The top-ranked American on Tour – on Sunday, he defeated Milos Roanic – and is back in the US Open Quarterfinals for the first time since 2011. The past six months…have been extraordinary. In Miami, he defeated three top-10 opponents to capture his first Masters-1000 title; and a week later, helped lift Team USA back into the Davis Cup Semifinals. At Wimbledon, he reached his first Grand Slam Semifinal – setting a tournament record, pounding 214 total aces – and returned to the States with a career-high ranking of World #9. He then won his 6th consecutive title at the US Open Series event in Atlanta, and now owns 14 career ATP World Tour Singles titles. Competing in his 12th US Open, from Greensboro, North Carolina – Please welcome the #1 American…John Isner.