Stanislas Wawrinka booked an all-Swiss semi-final with Roger Federer at the ATP World Tour Finals after overcoming Marin Cilic in three sets at the O2 Arena in London.
Wawrinka only needed three games to progress to a second straight semi-final at the season-ending tour finals and after holding in his opening two service games, he broke the US Open champion decisively to guarantee his place in the last four.
The Swiss No.2 eventually took the match 6-3 4-6 6-3 and progresses to the knock-out phase with two group stage wins while Cilic's miserable maiden appearance at the World Tour Finals ends with his third straight defeat.
Despite the minor task at hand, Wawrinka began with the same authority which had delivered him his maiden grand slam title at the Australian Open, with successive holds thanks to a handful of typically clinical backhand winners.
Cilic held in his opening service game also but then came the critical moment, when trailing 2-1 Wawrinka produced a stunning cross-court backhand to help set up three break points, taking the second as the Croatian sent a volley into the tramlines.
Though both players' fate was now sealed, important ranking points, if not end of season pride remained up for grabs and it was Wawrinka who took a grip of the first set before clinching it 6-3 as Cilic failed to break through the No.3 seed's dominant serve.
The 29 year old Cilic provided sterner resistance in the second set and after holding to lead 5-4 he forced a string of errors from Wawrinka to square the match and force a third set for just second time in the singles competition this week.
Early exits in Tokyo, Shanghai, Basel and Paris had worked to undermine the twilight of Wawrinka's season and that inconsistency returned in the third set as Cilic grabbed an early break to grab a 2-0 advantage.
But the break only worked to inspire Wawrinka, who reeled off six of the next seven games to progress on a winning note and set himself up perfectly for a meeting with Davis Cup teammate Federer.