Thiem battles past Donskoy in season-opener at Doha

The world number 5 won a staggering 92 percent of his first serve points to hold off a battling Donskoy, who pushed the 24-year-old to the brink in the opening set, and regained control in the second set to charge to victory.

"It was a good victory because (of a) tough opponent... after a pretty long period without any matches," Thiem said. "After a good start, it got pretty close in the first set... at the end I'm satisfied with most parts of my game."

Thiem will play either Slovenia's Aljaz Bedene or Tunisian wildcard Malek Jaziri in the second round.

Spaniard Fernando Verdasco also had to fight for victory after losing the first set against Israel's Dudi Sela but the seventh-seed staged a comeback to win the final 10 games of the match and record a 4-6 6-4 6-0 win.

Verdasco will face Andrey Rublev in the second round after the Russian was handed a win as German Cedrik-Marcel Stebe retired with the score at 6-1 in the 20-year-old's favour.

Georgia's Nikoloz Basilashvili, who beat Italy's Thomas Fabbiano 6-4 6-3 on Monday, will play the winner of the match between second seed Pablo Carreno Busta and Borna Coric.