Fifteen-year-old American Coco Gauff said she's on "a mission to be the greatest" on Monday after stunning veteran Venus Williams once again in the first round of a Grand Slam.

Serena Williams and Roger Federer avoided chaos caused by rain at the Australian Open on Monday as heavy downpours forced organisers to postpone a swathe of matches on the first day.

Old stagers Novak Djokovic and Serena Williams will aim to keep the younger generation of players waiting in the wings as Grand Slam tennis enters a new decade at the Australian Open on Monday.

Tempers flared at the Australian Open qualifying on Wednesday as players battled through another day of smoky air and two of the game’s all-time greats were labelled “selfish” for not protesting about the conditions.

Tennis superstars Roger Federer and Rafael Nadal jointly donated Aus$250,000 (US$172,000) for Australian bushfire relief at a charity fundraiser in smoggy Melbourne on Wednesday.

Tempers flared at the Australian Open qualifying on Wednesday as players battled through another day of smoky air and two of the game's all-time greats were labelled "selfish" for not protesting about the conditions.

World number one Ashleigh Barty survived a scare yesterday before battling through her opening match at the Adelaide International to beat Anastasia Pavlyuchenkova in three tough sets.

India's former doubles world number one Sania Mirza made a winning return to tennis Tuesday at the Hobart International after more than two years on maternity leave.

A player collapsed in a coughing fit and was forced to retire from Australian Open qualifying on Tuesday after organisers ploughed ahead with matches despite bushfire smoke plunging Melbourne's air quality to "hazardous" levels overnight.

An emotional Novak Djokovic overpowered long-time rival Rafael Nadal and led Serbia to victory in the inaugural ATP Cup yesterday, capping a perfect build up to his Australian Open title defence.

Rafael Nadal and Novak Djokovic will face each other in the final of the inaugural ATP Cup after winning epic three-set matches yesterday to steer Spain and Serbia into the decider.

Rafael Nadal suffered an upset singles loss but made amends in the doubles to keep Spain alive at the ATP Cup yesterday, with Novak Djokovic also surviving a scare before rallying to guide Serbia into a semi-final against Russia.

Tennis prodigy Coco Gauff was quick to rebuke her father for swearing on Wednesday -- when he said “damn” while coaching her during a match. Corey Gauff, father and coach of the 15-year-old sensation, was put in his place after his daughter took the first set against Laura Siegemund at the WTA Auckland Classic.

World number one Ashleigh Barty remains upbeat about her Australian Open preparations despite losing her opening match of the season at the Brisbane International yesterday.

Serena Williams found her power game after a sluggish start as she overcame qualifier Camila Giorgi to open her 2020 season with a straight-sets victory at the Auckland WTA Classic yesterday.

A near-perfect Novak Djokovic won both his singles and doubles rubbers as Serbia beat France 2-1 to reach the quarter-finals of the inaugural ATP Cup teams event in Brisbane yesterday.

John Millman stunned Felix Auger-Aliassime in straight sets to help guide Australia to victory over Canada in their ATP Group F tie in Brisbane yesterday.

Former world number one Maria Sharapova said yesterday she still had “a lot of fire” as she attempts to resurrect her career after an injury-plagued 2019.

Andy Murray has withdrawn from next month's Australian Open because of a pelvic injury, the three-time Grand Slam champion's management team announced on Saturday.

India's veteran tennis player Leander Paes announced on Wednesday that 2020 would be his "farewell year" as a professional before he hangs up his racket.