Australian Open | Djokovic, Osaka, Serena make flying starts

Kerber, Monfils and Nishikori fall at first hurdle; Andreescu makes winning return from injury.

Japan's Naomi Osaka in action during her first round match against Russia's Anastasia Pavlyuchenkova dring the Australian Open tennis tournament in Melbourne on Monday, February 8, 2021.

Novak Djokovic served a reminder of why he's the greatest Australian Open champion in history as he demolished France's Jeremy Chardy in straight sets in round one on Monday.

The eight-time winner's 6-3, 6-1, 6-2 win showed that normal service had resumed at Rod Laver Arena after the year's first Grand Slam was delayed three weeks owing to the coronavirus.

Serena Williams, Naomi Osaka and Simona Halep also enjoyed convincing wins as the tournament finally got underway in front of limited crowds after a troubled build-up.

Form and fitness are highly unpredictable after the coronavirus wiped out five months of last season and badly disrupted preparations, but Djokovic left little doubt about his readiness to pursue a record-extending ninth title in Melbourne.

Women’s third seed Osaka struck the first serve on centre court against Russia's Anastasia Pavlyuchenkova and strode out just 68 minutes later a 6-1, 6-2 winner.

Williams started her quest for a record-equalling 24th Grand Slam title in style with a 6-1, 6-1 romp past Germany's Laura Siegemund in 56 minutes.

Later, the 2019 US Open champion Bianca Andreescu won an emotional first match after 15 months out against Romania's Mihaela Buzarnescu 6-2, 4-6, 6-3.

The 20-year-old Canadian last played at the WTA Finals in October 2019 at Shenzen, China, where she suffered the knee injury that scuppered her entire 2020 season.

But Angelique Kerber, the 2016 Australian Open winner, was the first significant casualty of the women's championship when the 23rd-seeded German lost 6-0, 6-4 to 63rd-ranked American Bernarda Pera.

In the men's draw, US Open champion Dominic Thiem was made to work hard in the first set by Kazakh veteran Mikhail Kukushkin before coming through 7-6(2), 6-2, 6-3.

Sixth seed Alexander Zverev dropped a set and smashed a racquet before grinding to a 6-7(8), 7-6(5), 6-3, 6-2 win against American Marcos Giron.

Meanwhile, Gael Monfils, the French 10th seed, was stunned 3-6, 6-4, 7-5, 3-6, 6-3 by Emil Ruusuvuori of Finland, the World No. 86.

Japan's Kei Nishikori also fell at the first hurdle with a straight-sets defeat to Pablo Carreno Busta of Spain.