Jack Sock overcame a dose of the flu to score an upset win over top-seed David Ferrer in the ATP Auckland Classic on Friday to set up a final showdown against Roberto Bautista Agut.

Sock won his semi-final 3-6, 6-1, 6-2 to dash Ferrer's hopes of a record fifth title in Auckland, while Bautista Agut also came from a set down to beat the second seed Jo-Wilfried Tsonga 3-6, 7-6 (7/3), 6-4.

Charismatic Sock, ranked 26, complained of feeling unwell before the match and was a doubtful starter.

But at the end he joked that perhaps it would be best if he stayed unwell for the Australian Open as illness brought out the best in him.

After losing the first set, Sock required medical attention before fighting back with a performance reminiscent of the quarter-final when he came from behind to beat Kevin Anderson 1-6, 6-4, 6-4.

Sock, 23, raced to a 5-0 lead in the second set using his powerful forehand with unerring accuracy, before winning 6-1.

He broke again at the start of the deciding set and remained in control before finishing the match with a second-serve ace.

"It was a difficult day. I woke up with some flu-like symptoms. I didn't know if I was going to play," said Sock, who at the end of the match produced his newly adopted trademark of throwing a sock into the crowd.

"I ended up coming out and playing some of the best tennis of my career. Maybe I can stay sick through Melbourne and play like this."

Sock has only one tour title to his credit, but with the poise he showed against more experienced Ferrer, 33, the stage is set for a thriller of a final against Bautista Agut who is ranked one spot ahead of the American at 25.

After losing the first set to Tsonga and dropping his first serve at the start of the second, Bautista rallied to fight off a match point before taking the second set in a tiebreak.
Source: AFP