"I was more busy with myself, and I was struggling myself," Haase said. "I tried to play my game. It didn't bother me what he did."
No such struggles for top-seeded Novak Djokovic, who breezed past U.S. Open novice Diego Schwartzman 6-1, 6-2, 6-4. Djokovic wrapped up the final match on opening day at the year's last Grand Slam event as the hour grew late, with fans calling out to him from the far-away seats at Arthur Ashe Stadium.
"I hope it was a midnight delight for all you guys," he told them in an on-court interview.
Fifth-seeded Maria Sharapova, who missed last year's tournament because of an injured right shoulder, made a successful return by winning the final 10 games to beat Maria Kirilenko 6-4, 6-0 in a matchup of 27-year-old Russians and longtime friends. Actor Alec Baldwin got into the action, too, catching an out-of-bounds shot that sailed over Sharapova and bounced into the seats.
Also, 10th-seeded Caroline Wozniacki of Denmark advanced 6-1, 3-6, 2-0 when Magdalena Rybarikova of Slovakia had to stop because of an injured left hip.
Ninth-seeded Jo-Wilfried Tsonga also needed four sets to beat Juan Monaco 6-3, 4-6, 7-6 (2), 6-1. Nick Kyrgios — the Australian teen who stunned Rafael Nadal at Wimbledon — came back from three code violations, just one outburst away from default, in a 7-5, 7-6 (4), 2-6, 7-6 (1) upset of 21st-seeded Mikhail Youzhny.
Julien Benneteau, seeded 24th, was upset in five sets by fellow Frenchman Benoit Paire.
Third-seeded Stan Wawrinka and fifth-seeded Milos Raonic both advanced in straight sets.
Top-seeded Novak Djokovic played later under the lights at Arthur Ashe Stadium in the first night session of the year's last Grand Slam tournament.
Earlier, Venus Williams, 34, beat 43-year-old Kimiko Date-Krumm 2-6, 6-3, 6-3. The combined age of 77 was believed to be the oldest for a women's Grand Slam pairing, the WTA said.
Along with the 19th-seeded Williams, 21st-seeded American Sloane Stephens also advanced by routing Annika Beck.
Second-seeded Simona Halep rallied from a set down for a 6-7 (2), 6-1, 6-2 victory over 20-year-old Danielle Rose Collins, who was playing her first main draw match at a tour-level event. As a sophomore at Virginia, an unseeded Collins won the NCAA title to earn a wild card into the U.S. Open.