LONDON, Nov. 16 (Xinhua) -- Austrian Dominic Thiem ousted defending champion Alexander Zverev of Germany 7-5, 6-3 here on Saturday, booking a final fight against Greek debutant Stefanos Tsitsipas for the trophy of the ATP World Tour Finals.
Thiem came to London in sharp form as the 26-year-old defeated six-time champion Roger Federer and five-time winner Novak Djokovic back-to-back in group stage. The world No. 5 played well in his service games on Saturday but seemed struggled when his opponent executed his first serves with an average speed above 250 kmph.
Thiem grabbed a chance to break with brilliant returns in the 12th game, had another break in the sixth game of the second set, reaching the final for the first time after qualifying for the season-ending finale four years in a row.
"This is just a big, big dream coming true for me. It is one of the best tournaments all year, one of the most prestigious tournaments all year, and I'm getting the chance to play the final tomorrow. It's unreal to me," said Thiem.
Tsitsipas also clinched a "dream win" as he knocked out Federer 6-3, 6-4 in an earlier semifinal.
"It's a great moment not just for me, for everyone else, my country, my team. I'm proud of myself, how hard I fought today, how concentrated I stayed in the breakpoints. Didn't crack under pressure. I was very composed and very mature in my decisions," said the youngest in the top eight.
Thiem felt happy that both finalists are one-handed backhand. "We are both very offensive players, he's very attractive to watch. I love to watch him, so I'm really looking forward to playing," he said.