New York - Third seed Roger Federer battled to defeat 19-year-old American Frances Tiafoe in five sets to reach the US Open second round on Tuesday night in New York.
The Swiss 19-time grand slam winner needed 2hr 37min to down Tiafoe 4-6, 6-2, 6-1, 1-6, 6-4 to set up a second round meeting with either Slovenian Blaz Kavcic or Russian Mikhail Youzhny.
The state of Federer’s back injury remains a concern for fans, which happened over two weeks ago during the final in Montreal.
In his on-court interview with Tom Rinaldi after his victory, the 36-year-old admitted that his back injury concerns were responsible for his slow start.
"I was maybe a bit worried with my back issue from a couple of weeks ago," said Federer, "but eventually I was able to let go."
Rinaldi then asked Federer how he was feeling physically. "Extremely well, I wasn’t here last year. I’m here this year so things are much, much better.
"To get through a five-setter you have to be okay somehow," Federer said. "So I believe this is going to give me great confidence in the body and also in my game because preparation was a big compromise."
Later in his press conference, the Swiss was asked more questions by reporters about his slow start, Federer replied, "I don't think I had the preparation I was hoping to get. Since Montreal, the focus has been more on the back, making sure I can play the tournament rather than being well-prepared. I always knew I was going to come in feeling rusty or not great.
"I really struggled early on. I think Frances connected well. I kind of lost my footing sometimes. My eye wasn't working. I was misjudging distance. I think I was also being a bit cautious with my movement.
"Then in the second set, it all started to come together. That was good. But because of the preparation being not the best that I've had, I was quite up and down."
He was then asked about his "dodgy" back. "I'm very happy that I'm feeling as good as I'm feeling right now," Federer said. "If I had felt that my back was going to get worse every match, I probably wouldn't have played.
"My hope and my belief is that it's only going to get better from here because every day that goes by puts me further away from what happened in Montreal."