Dominant at the Atlanta Open previously, John Isner was downed by Reilly Opelka in the second round.

Opelka ends Isner's Atlanta Open title defence

John Isner's bid for a sixth Atlanta Open title came to an end in a second-round loss to Reilly Opelka on Wednesday.

The big-serving Americans were unable to break before Opelka edged a 7-6 (7-2) 6-7 (5-7) 7-6 (7-5) victory.

Top seed Isner served 33 aces and Opelka sent down 31 at the ATP 250 event played on hard-courts in Georgia.

A five-time champion and three-time runner-up at the tournament, Isner bowed out after his third loss to Opelka this year.

This year will be just the second time Isner has not reached the final in Atlanta and first since 2012.

Two-time defending champion Isner was one of three seeds to fall as Pierre-Hugues Herbert and Radu Albot also departed.

Herbert went down to Alexei Popyrin 7-5 6-3 and Albot suffered a 7-6 (7-5) 5-7 6-2 loss to Dan Evans.

In the day's other match, Cameron Norrie was too good for qualifier Kwon Soon-woo 6-3 6-4.

Jaziri wins again in Dubai

Jaziri shines on despite floodlight failure in Dubai

Following his upset win against Grigor Dimitrov, Malek Jaziri marched on at the Dubai Tennis Championships on Wednesday.

Stephens survives in Acapulco

Stephens survives in Acapulco, Tsurenko eases through to quarters

US Open champion Sloane Stephens advanced in Acapulco thanks to Wednesday's 5-7 7-6 (8-6) 6-0 victory over Dutch qualifier Arantxa Rus.

Del Potro outlasts Ferrer

Del Potro outlasts Ferrer as Zverev and Thiem advance

Juan Martin del Potro made it through to the last eight by outlasting Spanish veteran David Ferrer 6-4 4-6 6-3 in Acapulco on Wednesday.

Wawrinka ends hard-court season

Wawrinka to miss Indian Wells and Miami Open

Stan Wawrinka feels he would be better off on the practice courts rather than playing at Indian Wells or in Miami.

Del Potro, Zverev win in Acapulco

Del Potro, Zverev into Acapulco semis

Juan Martin del Potro and Alexander Zverev will meet at the Mexican Open after quarter-final wins.