The Austrian world No. 8, already beaten by Anderson and Federer in his first two round-robin matches, broke twice in the first set and took advantage of Nishikori's 42 errors to keep his faint hopes of qualification alive.
"I really want to play a good match", Thiem said.
Last month, 20-time Grand Slam champion Federer revealed that he has been struggling with a hand injury since this year's grasscourt season.
Benneteau, a French journeyman who reached a career-high ranking of 25, was particularly referring to the Australian Open, a tournament Federer has won on six occasions. "And he played 12 or 13 of them in the night session", Benneteau told France's RMC Sport.
Kei recovered his game a little bit in set number two, holding easily three times and saving a break point in game five with a backhand volley victor in one of the best moments of the entire match. "I'd rather put it to rest rather than adding to it so you guys got something to write about".
The South African did not face a single break point in his first two matches but was broken four times on Thursday night against Federer, who got revenge for his quarter-final loss to Anderson at this year's Wimbledon. The semi-final lineup could possibly look like Djokovic vs Anderson and Federer vs Sascha Zverev, but John Isner may yet upset the German's chances in the Friday afternoon match.
"I was just not happy at the end of the tournament in Australia because they changed the rules, "Cilic said".
Tiley said: "In terms of players and their appeal, it needs to be said that Roger Federer is a once-in-a-generation player widely regarded as one of the biggest "box office" athletes in the world". Sometimes they ask me, you know, Asia wants you to play at night.
Djokovic said, "I understand Julien's point because sometimes it does seem that maybe certain players get more favored".
Roger Federer beat Kevin Anderson in straight sets to qualify for the knockout stages of the ATP Finals and top Group Lleyton Hewitt.
Tennis Australia chief Craig Tiley has launched a defense over claims that the Australian Open officials favor Roger Federer when it comes to scheduling matches.
"I felt fresh, but I just didn't feel the ball this week", said Nishikori.
With this win, Federer will head into the next stage from the first place in Lleyton Hewitt group, and his opponent might be Novak Djokovic, who is now first in the Gustavo Kuerten group. I'm thrilled to be in the semis. Much to the surprise - and disappointment - of the partisan crowd at the O2 Arena, the Swiss great handed the break straight back with a series of errors.