Chennai - Twice champion Stanislas Wawrinka sailed into the Chennai Open semi-finals on Friday, staving off Gilles Mueller's late challenge en route to a 6-2 7-6(4) victory.
In their first ever meeting, Australian Open champion Wawrinka broke his opponent from Luxembourg in the opening game and pocketed the first set of the quarter-final quickly.
Mueller, however, refused to throw in the towel and took a 4-2 lead in the second before Wawrinka rallied to level it 4-4 and force a tie-breaker in which the Swiss world number four prevailed.
"Gilles is a big-server, left, it's tough returning but I'm happy," Wawrinka, who meets fourth seed David Goffin in the semi-final, said in a courtside interview.
Spaniard Roberto Bautista will meet Slovenia's Aljaz Bedene in Saturday's other semi-final.
AFP supplied the following quarter-finals results:
Roberto Bautista-Agut (ESP x3) bt Yen-Hsun Lu (TPE x6) 7-6 (9/7), 6-4;
Aljaz Bedene (SLO) bt Guillermo Garcia-Lopez (ESP x5) 2-6, 6-3, 6-2;
David Goffin (BEL x4) bt Andreas Haider-Maurer (AUT) 7-5, 6-2.