Dubai - Stan Wawrinka reached his second final of the season on Friday when bitter rival Nick Kyrgios retired injured from their much-anticipated Dubai ATP showdown.
French Open champion Wawrinka was leading 6-4, 3-0 when the brash Australian quit due to back pain, having required on-court treatment after the seventh game of the opening set.
"I was never going to be able to really make too much of an impact in the match with the way I was serving," Kyrgios said. "I've been feeling so bad every day.
"I seem to have some kind of viral infection. I couldn't really serve anywhere near my full capacity and he was playing great anyway. It was a bit of a struggle, to be honest."
In Saturday's final, Wawrinka will take on rejuvenated Marcos Baghdatis who defeated Spain's Feliciano Lopez 3-6, 7-6 (7/1), 6-1.
Lopez had made the semi-finals on Thursday when world number one Novak Djokovic retired from their clash with an eye infection.
Kyrgios now faces a race against time to be fit for next weekend's Davis Cup first-round tie against the United States in Melbourne.
There was no sign of any hard feelings between the outspoken Kyrgios and Wawrinka as they played for the first time since the Australian directed a crude sex slur over Wawrinka's girlfriend, WTA star Donna Vekic during a heated match last August in Montreal.
"The tension was there because it's a semi-final and I don't want to lose. I want to win," Wawrinka said.
"I want to play better tennis. I want to be in the final and have a chance to get the trophy.
"That's why I get the tension. But the rest, there wasn't, from my side, anything special."
Wawrinka, playing in Dubai for the first time in eight years and without a win prior to this week, went up a double break in the opening set but lost it.
The 30-year-old Swiss earned his third break for a 5-4 lead and served out the set in the next game.
Kyrgios's level dropped in the second set, with the world number 33 giving up after losing three straight games.
Wawrinka now moves into position for a possible second trophy of the season after winning in Chennai to start the year. He stands 5-0 over Baghdatis.
Wawrinka, ranked fourth in the world, carries an enviable record into Saturday's title match at the Aviation Club, having won his last eight finals.
Kyrgios, 20, ran out of energy after winning his first career ATP title last week in Marseille and travelling directly to the Gulf.
His win streak of nine consecutive matches was ended by Wawrinka in 44 minutes.
"He wasn't really there from the beginning, wasn't serving his best," Wawrinka said.
"But you never know what to expect, with him. I was focused on myself. I wasn't expecting anything. I was trying to play my game, to stay tough, stay there, trying to win every point and that's it."
Baghdatis will play his first final since last summer in Atlanta and is seeking his first trophy since 2010, when he won Sydney.
The Cypriot, a Dubai semi-finalist in 2010, managed to finally get a read on the tricky Lopez lefty serve as he slowly reversed his fortunes over two hours.
"I couldn't serve at all at the start," said the former Australian Open finalist. "Feliciano was serving great and I could not read it.
"But at the end of the second set, his level dropped and I started reading the serve better, guessing the right side and playing better.
"I'm really happy to win into this tough final against Stan, he's a great player."
Results on the fifth day of the ATP Dubai Championships on Friday (x denotes seeded player):
Marcos Baghdatis (CYP) bt Feliciano Lopez (ESP x6) 3-6, 7-6 (7/1), 6-1
Stan Wawrinka (SUI x2) bt Nick Kyrgios (AUS) 6-4, 3-0 - retired