Another win for Tsonga, Gulbis wins serving battle with Isner
Tommy Haas made life tough for Jo-Wilfried Tsonga at the Erste Bank Open, but the in-form Frenchman did enough to secure victory.
Jo-Wilfried Tsonga maintained his push for a place at the ATP World Tour Finals by edging out Tommy Haas in round one of the Erste Bank Open.
Tsonga has risen to ninth in the Race to London following a fine sequence of results, including a run to the final of last week's Shanghai Masters.
And the Frenchman avoided an early upset in Vienna, albeit having been made to battle hard by his veteran opponent before completing a 6-3 6-7 (3-7) 6-4 victory.
Second seed Kevin Anderson was predictably strong on serve as he also came through his opening match against Andreas Haider-Maurer.
A break in each set saw the South African triumph 6-4 7-5 to book a meeting with Jiri Vesely.
In second-round action, third seed John Isner was surprisingly defeated by Ernests Gulbis 6-4 4-6 6-4.
Gulbis was ranked as high as 10th in July 2014, but has plummeted down the rankings and is currently 104 spots below his American opponent.
Isner has a reputation for big serving, but his 16 aces were outdone by Gulbis' impressive 23.
While Isner will play no further part, eighth seed Fabio Fognini overcame a second-set scare to beat Paul-Henri Mathieu 6-4 3-6 6-3.
And seventh seed Ivo Karlovic also avoided an upset, giving up just nine points on serve as he claimed a 6-4 7-5 win over Sergiy Stakhovsky, who was unable to force a single break point.