NEW YORK (AFP) - Roger Federer recorded his 80th US Open win and 17th in 17th meetings with grizzled Russian Mikhail Youzhny on Thursday to reach the men's singles last 32, where he was joined by Andrey Rublev, the latest teenage upstart in New York.
Federer, 36, needed a second successive five-setter to reach the third round with a 6-1, 6-7 (3-7), 4-6, 6-4, 6-2 win over fellow veteran Youzhny, just one year his junior.
The five-time champion had also needed five sets to see off American teenager Frances Tiafoe in the first round.
The 36-year-old next faces another 35-year-old, Feliciano Lopez of Spain, for a place in the last 16. His record against Lopez is just as solid - 12-0.
"It was quite a lot of fun out there - I feel quite warmed up by now," said Australian Open and Wimbledon champion Federer, who fired 63 winners and 68 unforced errors.
Youzhny admitted he had cramped, which meant he could move left to right but not forward and back.
Rublev became the second teenager to make the third round when he stunned Bulgarian seventh seed Grigor Dimitrov 7-5, 7-6 (7-3), 6-3. Rublev, just 19 and the world No. 53, joins 18-year-old Denis Shapovalov of Canada in the last 32 at a Grand Slam event for the first time.
"It's an amazing feeling. I'm very happy to win this match," said Rublev after stunning Cincinnati Masters champion Dimitrov.
Also going through to the last 32 was 2009 champion Juan Martin del Potro, the 24th seeded Argentinian, who saw off Spanish qualifier Adrian Menendez-Maceiras 6-2, 6-3, 7-6 (7-3).
A record was set when American Shelby Rogers and 25th-seeded Australian Daria Gavrilova played out the longest ever women's singles match. Their 3hr 33min clash saw Rogers win 7-6 (8-6), 4-6, 7-6 (7-5) on a fifth match point in a final set that lasted 90 minutes.
Their second-round tie on Court 10 went past the previous longest of the 3hr 23min it took Johanna Konta to beat Garbine Muguruza in the second round two years ago.
Karolina Pliskova had to battle back from a set down to make the last 32 and hang on to her world No. 1 spot. The Czech player, who was runner-up in 2016, downed American qualifier Nicole Gibbs 2-6, 6-3, 6-4.