Jack Sock claimed his second ATP World Tour title with a three-set win over Joao Sousa in the ASB Classic final.

The American fought his way to a 6-3 5-7 6-3 victory over Portugal's Sousa in Auckland on Saturday.

Sock sent down 13 aces in his win at the ATP 250 event, securing his second title and first since April 2015.

The 24-year-old, who had lost his only previous meeting with Sousa, was a finalist at the ASB Classic last year.

He had to come from a break down in the third set as he fell 2-1 behind, only for Sousa to fail to consolidate.

Sock broke again in the eighth game before closing out his win in one hour, 56 minutes.

Sousa, who faces Jordan Thompson in the Australian Open first round, saw his record in ATP finals slip to 2-6.

Sock's opening match at Melbourne Park is against Frenchman Pierre-Hugues Herbert.