New York, United States (AFP) — Three-time defending champion Serena Williams launched her quest for a historic title Monday by overwhelming 86th-ranked Russian Vitalia Diatchenko and advancing to the second round of the US Open.

The world number one was a 6-0, 2-0 winner after only 30 minutes at Arthur Ashe Stadium when Diatchenko retired with a left foot injury, advancing Williams into a second-round match against Dutch qualifier Kiki Bertens.

“If I can just stay relaxed and stay in the points and stay calm and happy out there, I have to look at it as I have nothing to lose,” Williams said.

The 33-year-old American chases the first calendar Grand Slam since Steffi Graf in 1988 and a 22nd career major title to match Graf’s Open Era record, two shy of Australian Margaret Court’s all-time mark.

Williams praised the loud New York crowd, which has adored her since she captured her first major title at the 1999 US Open as a teen prodigy.

“I felt the support and love on this journey and milestone I’m trying to take one match at a time,” Williams said.

“I feel so good. I’m so ready. I’m at home, where it all began for me in ’99. It all feels great.”

Top-ranked Novak Djokovic and eighth seed Rafael Nadal also cruised into the second round on the men’s side, but Japanese fourth seed Kei Nishikori crashed out after his US Open runner-up effort last year.

Djokovic needed only one hour and 11 minutes to capture a 6-1, 6-1, 6-1 victory over Brazil’s Joao Souza.

“There’s something I love about number one for sure,” said Djokovic, who plays Austrian Andreas Haider-Maurer next.

“Hopefully I can keep it up. If I can, I feel I have a really good chance against anybody.”

Nadal, in his first US Open match since winning in 2013 after missing 2014 with an injury, avenged a loss last year at Basel to Croatian teen Borna Coric with a 6-3, 6-2, 4-6, 6-4 victory, booking a date with Argentina’s Diego Schwartzman.

“I missed a lot this fantastic crowd that gave me unbelievable support,” Nadal said. “Very happy to be back and be through.”

Djokovic’s highest-ranked possible semi-final foe had been Nishikori, but the Asian number one exited the US Open at the first match for the third time in five years as France’s 41st-ranked Benoit Paire saved two match points to win 6-4, 3-6, 4-6, 7-6 (8/6), 6-4.

“To beat Nishikori, for me, it was impossible to imagine this,” Paire said. “I’m really happy.”

Paire, who had never before beaten a top-five foe, fired 21 aces to only three for Nishikori and blasted 64 winners, 30 more than Nishikori.

“He was very aggressive, so there were many rallies and it was tough to get rhythm,” Nishikori said.

Nishikori led the tie-breaker 6-4 but swatted a forehand long, watched Paire smack two service winners and then Nishikori netted a forehand to force a fifth set.

Paire, who won his first ATP title last month at Bastad, broke for a 3-2 lead and held to the finish to win after three hours and 14 minutes.

Reigning champion Marin Cilic of Croatia won his opener 6-3, 7-6 (7/3), 7-6 (7/3) over Argentine qualifier Guido Pella.

“Defending a Grand Slam title for the first time for sure is something I will learn from,” Cilic said.

Williams lost plenty of potential obstacles in her march to history on day one as top-10 women’s seeds Ana Ivanovic, Karolina Pliskova and Carla Suarez Navarro exited with opening-match losses.

That left 12th seed Belinda Bencic — who ousted Bulgarian Sesil Karatancheva 6-1, 6-2 — as the top-rated foe in Williams’ half of the draw. Williams, who lost to Bencic in the Toronto semi-finals, could see the Swiss teen again in a quarter-final.

Williams, who owns six US and Australian Open and Wimbledon titles plus three French Open crowns, won her 22nd US Open match in a row since her last loss, to Aussie Samantha Stosur in the 2011 final. Williams has won eight Slam titles since then.

Slovakia’s 50th-ranked Dominika Cibulkova ousted seventh-seeded Ivanovic 6-3, 3-6, 6-3, delivering the Serb star’s earliest US Open exit since 2009.

After the injury-forced withdrawal of Russian third seed Maria Sharapova, Ivanovic had been Williams’ top-ranked rival in her half of the draw.

That status fell to Czech eighth seed Pliskova, who promptly lost to American Anna Tatishvili 6-2, 6-1, and then to 10th seed Suarez Navarro, who fell to Czech Denisa Allertova 6-1, 7-6 (7/5).

One Williams rival who advanced was her older sister Venus, a seven-time Grand Slam champion. The US 23rd seed outlasted Puerto Rico’s Monica Puig 6-4, 6-7 (7/9), 6-3.