Former champion Lleyton Hewitt's revival at the U.S. Open was triggered by a marathon day of training with Roger Federer on the opening day at Flushing Meadows, the hardnosed Australian revealed.
The 32-year-old Hewitt, 2001 champion in New York, advanced to his first fourth round appearance at the U.S. Open since 2006 with a 6-3 7-6(5) 3-6 6-1 win over Evgeny Donskoy and will take on another Russian in seasoned 21st seed Mikhail Youzhny.
Hewitt said he had contacted Federer's coach Paul Annacone to set up a hit with Federer and they ended up having two training sessions on the same day.
"Roger and I have hit quite a bit the last couple of years," the former world number one told reporters. "I've had some really good practice sessions with him.
"I was surprised that Roger was here Monday morning and wanted to hit at ten o'clock. We hit for two hours, then another two hours in the afternoon.
"At least I got used to center court, which was a bonus. It was funny, we didn't do any points at all. We just did drills for four hours."
Hewitt heard on the grapevine that Federer had described him as a 'role model' earlier in the year.
"Yes, someone mentioned it to me," said Hewitt, ranked 66th in the world.
"Obviously he's dropped from four to seven (on the rankings). Not quite as low as mine. I've been in the same situation as him, but not on such a great scale.
"When you've been to the top, you want to keep playing. The reason you're playing is for the majors. For me, Davis Cup as well.
"That's the reason I'm still playing. For him, I'm sure it's the majors. I have no doubt about it. He wants to squeeze the absolute most out of himself. Good on him."
The same age, Hewitt and Federer moved through the junior ranks together but it was the Australian who bloomed first, reaching world number one three years before Federer scaled the peak in 2004.
The Swiss master caught glimpses of Hewitt's upset of Argentina's sixth seed Juan Martin del Potro on Saturday night.
"I thought that Lleyton had a chance going in. I practised with him earlier this week, I think on Monday for three hours, and he was looking great. I'm very happy for him.
"He's been one of my biggest rivals on tour, so I always like to see him do well, particularly here under the lights in New York. He deserves it. He's gone through a lot, you know, and I was very happy for him personally."
Hewitt, who has battled a succession of debilitating injuries in recent years, famously won the 2001 Wimbledon final against Argentine David Nalbandian without approaching the net at all, but raided the net more than 30 times against Donskoy, successfully on most occasions.
"I felt like I could dictate play and come in," he said. "That's what i did right from the start to set the tone out there.
"If the right ball is there, I think I'm a good enough volleyer to back it up and play aggressive tennis."
Hewitt holds a 5-1 winning record over 31-year-old Youzhny, a clever all-court player with a former world ranking of eight and a solid record of going deep in the grand slams.
But the Australian may need to summon all of his fighting qualities against the Russian, who was superb in a 6-3 6-2 2-6 6-3 upset of 12th seed Tommy Haas.
Youzhny kicked an advertising hoarding in frustration while losing control of the third set against the evergreen German but hit back with a succession of spectacular winners to close out the match.