Isner beat the Frenchman 6-3 7-6 (7/4) 5-7 6-3 as USA took an unassailable 3-1 lead in the series to set up a last four clash with Spain.

Big-serving Isner built on the team's momentum after winning Saturday's doubles in straight sets, without facing a break point, while the pressure was clearly on the sixth-ranked Tsonga to level the match.

While Tsonga created plenty of chances, he could only break Isner's serve once in the match at the Monte Carlo Country Club.

"I gave everything I could in the battle," Tsonga said. "I didn't have much luck today and John took his chances. At 0-3 down in the fourth set, it became 'Mission Impossible.'"

Austria out

Meanwhile, David Ferrer secured defending champions Spain a place in the semi finals by beating Austria's Jurgen Melzer 7-5 6-3 6-3 to set up an insurmountable 3-1 series lead.

Despite his unsteady serve and gusting winds, the fifth-ranked Ferrer had little trouble remaining perfect in 14 matches on home clay en route to recording Spain's first win over Austria in 33 years.

Ferrer broke Melzer in the last game of an evenly-contested first set and didn't let up to claim Spain's 23rd straight home win, moving them into second place all time for consecutive home wins behind Italy's record of 28.

Spain captain Alex Corretja said he was happy to face USA in September's semis.

"It's great news since we will play at home in front of our fans," Corretja said. "We now have four or five months for our guys to get prepared."

Meanwhile, Tomas Berdych needed three tie-break sets to beat Janko Tipsarevic and send the Czech Republic into the last four.

The world No 7won 7-6 (8-6) 7-6 (8-6) 7-6 (9-7) in three hours and 45 minutes to give the Czechs an unassailable 3-1 lead at the O2 Arena in Prague.

It was Berdych's third winning rubber of the tie - all in straight sets - and means his country will face the winner of the other quarter-final between Argentina and Croatia.