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 No 1 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. The 33-year-old American chases the first calendar Grand Slam since Steffi Graf in 1988 and a 22nd career major title to Graf’s Open Era record, two shy of Australian Margaret Court’s all-time mark.

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 Joao Souza.

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.

Djokovic’s highest-ranked possible semi-final foe had been Nishikori, but the Asian No 1 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.

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.