SHANGHAI World number nine Gilles Simon dismissed Radek Stepanek 6-1 6-4 to win his final group encounter at the Masters Cup but will have to wait for Friday's second match to see whether he progresses to the last four.
The 23-year-old, who won his ticket to the season finale when world number one Rafael Nadal withdrew injured, finished with a 2-1 record in the round robin but his fate hangs on the outcome of Roger Federer's match against Andy Murray.
"It is not an easy situation since my qualification does not depend on my match," Simon, who would be the first Frenchman in the knockout stage since Sebastien Grosjean in 2001 if he goes through, told Canal Plus TV.
"I still have to wait a bit, it's frustrating but I'll reach at least a career-high seventh place in the ATP rankings.
"It's weird because in a couple of hours, I will either prepare for a semi-final match or just pack my things."
Czech world number 27 Stepanek came in at the last moment as a replacement for injured American Andy Roddick Wednesday and, with nothing to play for, struggled to contain the dynamic young Frenchman.
Simon claimed the first set when the Czech netted after just 25 minutes and encountered only marginally more resistance in the second.
"For me it was just an honour to be here, it was a great experience and a great motivation for next year," said Stepanek, who will be 30 later this month.
"Gilles played a great match ... I tried to play my best tennis here this week."
Swiss defending champion Federer, who lost his opener to Simon Monday, will win the group and claim a place in the semi-finals alongside Murray if he beats the in-form Briton.
(Additional reporting by Julien Pretot; Editing by Sonia Oxley)