Roger Federer flicked a final winner, trotted to the net and started to shake hands. Then, there was one last challenge.
Playfully, Thiago Alves called for a replay review.
So the man trying for his fifth straight U.S. Open title and an overmatched qualifier shared a laugh, watching together as the giant scoreboards above Arthur Ashe Stadium confirmed the call: The ball landed squarely on the line, Federer had won 6-3, 7-5, 6-4 Friday to advance to the third round.
Federer swept a guy ranked 137th, someone who spent this year in the minors and was playing his first tour-level event of the season. Still, it was hardly a breeze.
"The depth in men's tennis is immense," Federer said.
On the women's side, it is shaping up as even more of a scramble.
A day after No. 1 Ana Ivanovic lost to 188th-ranked Julie Coin, third-seeded Svetlana Kuznetsova, who won the Open in 2004 and finished second last year, became the latest upset victim when Katarina Srebotnik beat her 6-3, 6-7 (1), 6-3.
"It can happen with everyone," said fifth-seeded Olympic champion Elena Dementieva, who moved into the fourth round by beating Anne Keothavong 6-3, 6-4.
Novak Djokovic, Nikolay Davydenko and Jelena Jankovic also advanced.
Third-seeded Djokovic beat Robert Kendrick 7-6 (8), 6-4, 6-4 and fifth-seeded Davydenko beat Agustin Calleri 6-4, 6-4, 7-6 (2).
Second-seeded Jankovic won another squeaker, playing 28 points in the last game to finish off Zheng Jie 7-5, 7-5. Jankovic needed more than two hours to beat the 37th-ranked Zheng after playing for nearly three hours in the second round.
In night matches delayed more than an hour by rain, No. 12 Marion Bartoli defeated No. 23 Lindsay Davenport 6-1, 7-6 (3), and No. 15 Patty Schnyder beat Magdalena Rybarikova 7-6 (4), 6-4.
Also, former Open champion Marat Safin lost to No. 15 Tommy Robredo, 4-6, 7-6 (4), 6-4, 6-0.
Federer is down to his last chance to win a Grand Slam this year, part of a tough season that saw him lose his No. 1 ranking to Rafael Nadal.
Though they well could meet in this final, Federer has not tracked his nemesis through the tournament and didn't watch Nadal wrap up his match Thursday night in straight sets.
"I schedule my life around my life, not his," Federer said, smiling. "I was expecting five sets. I was there for four and five, but he wasn't there anymore."
To Alves, Federer remains on top.
"He is the biggest player for sure. Nadal is playing good tennis this year, but for me Federer is the best one," he said.