A semi-final meeting between Roger Federer and Rafa Nadal at the US Open is still on the cards after both players came through difficult third round encounters.
Federer, who has been struggling with a back problem, looked in danger of an early exit against fellow veteran Mikhail Youzhny, before finally coming through in five sets. Meanwhile, Nadal had to come from behind in a three-hour endurance test against Japan's Taro Daniel.
The match between Federer and Youzhny appeared at first to be going according to form, with the Wimbledon champion taking the first set 6-1 against a player he had won all 16 previous meetings against.
However, with Youzhny upping his game and the 19-time Grand Slam winner appearing to lose mobility due to his back issues, the second set proved much tougher and eventually the Russian survived a set point on the Federer serve to take the tie-break.
Matters got worse for Federer as his opponent took the third 6-4 and, with his unforced error count mounting, a shock appeared on the cards.
Instead, he managed to dig deep to take the fourth set 6-4 and then take the decider 6-2, as a visibly wilting Youzhny was left barely able to run by the end.
Speaking in his on-court interview, Federer denied that his struggles were down to his back problems.
He added: "I felt different, completely different, the way it played and everything. But I'm really, really happy I got through.
"These five-set battles are actually quite a lot of fun and I feel quite warmed up by now."
Having won three five-set matches to win the Australian Open, there is no doubt that even at 36 Federer has the stamina to come through. While such lengthy matches may be energy-sapping, he can look to a number of other players who have survived two five-set matches in the opening rounds to come through, including Andy Murray in last year's French Open.
As it happened, Federer against Youzhny only took a little over three hours, around the same length of time it took Nadal to see off Daniel. The Japanese outsider won the first set before the world number one took the match 4-6, 6-3, 6-2, 6-2.
Fans booking corporate hospitality for the ATP World Tour Finals in November may hope to see Federer play Nadal at the O2 Arena, but if they are to meet in the last four they will need to perform better in the later rounds. Federer's next opponent is Feliciano Lopez, while Nadal faces Leonardo Mayer.
With this year's two Grand Slam winners stuttering and the three men who won the major tournaments last year missing the US Open with injury, there is a huge opportunity for others to shine. However, Grigor Dimitrov will not be the man as he crashed out in straight sets against 19-year-old Andrey Rublev, the French Open junior champion.
Today (September 1st) will be a chance for Wimbledon finalist Marin Cilic to continue his campaign for a second US Open title, as he takes on 29th seed Diego Schwartzman. British singles interest will focus on Kyle Edmund against rising Canadian star Denis Shapovalov.
Image: Getty, from Keith Prowse subscription