PERTH, Jan 3: A tournament-ending knee injury to American John Isner on Thursday handed Spain a berth in this weekend's final of the Hopman Cup.

The US pairing of Isner and Venus Williams were set to face Spain's Fernando Verdasco and Anabel Medina Garrigues on Thursday, with the winner to progress to Saturday's final.

However, Isner withdrew from the tournament on Thursday morning citing a right knee problem, handing Spain a 3-0 victory and passage into the final for the sixth time.

Spain have won the mixed teams title three times, most recently in 2010, when Tommy Robredo and Maria Jose Martinez Sanchez lifted the title against Great Britain's Laura Robson and Andy Murray.

“We are happy, of course, to be in the final,” Verdasco said.

Results: Group B: Spain bt United States 3-0 Men's singles: Fernando Verdasco (ESP) bt John Isner (USA) 6-0, 6-0 (walkover)

Women's singles: Anabel Medina Garrigues (ESP) bt Venus Williams (USA) 6-0, 6-0 (walkover)

(Exhibition match played: Venus Williams (USA) bt Anabel Medina Garrigues (ESP) 6-3, 6-4)

Mixed doubles: Medina Garrigues/Verdasco (ESP) bt Williams/Isner (USA) 6-0, 6-0 (walkover).—AFP