Tommy Haas battled back from a one-set deficit to defeat Nicolas Almagro in the standout match of day one of the Shanghai Masters.

Spaniard Almagro looked to be heading for a routine victory when he won the first set 6-4.

However, Haas responded in the second set to win a tie-breaker 7-4. The veteran then broke Almagro twice in the decider, before serving out for a 6-2 success.

Elsewhere, Marin Cilic progressed to round two at the expense of Lukasz Kubot 7-5 6-3, while Alexandr Dolgopolov also advanced 6-3 6-2 against France's Jeremy Chardy.

Tommy Robredo won 7-6 6-4 over Alex Bogomolov and Richard Gasquet knocked out Brian Baker 6-2 6-3.