The world number one remained on track to win her third consecutive Melbourne Park title but only after a rollercoaster scrap that lasted more than two hours on Rod Laver Arena.

Collins, 31, blew kisses to the fiercely partisan crowd, cupped her ear and even pointed to her backside after a stormy 7-6 (7/4), 4-6, 6-2 victory over Aiava, the last Australian woman in the draw.

Casey Wasserman, chairman of the LA 2028 organizing committee, met with Trump at his Mar-a-Lago residence on Wednesday and provided full backing despite some critics calling for the Olympics to be moved.

The left-handed Californian Tien soaked up the applause at Margaret Court Arena after the biggest win of his young career following four hours and 48 minutes of seesawing action.

On-court coaching, previously banned and punishable by point deductions, disqualification or even suspension from tournaments is being positively encouraged at Melbourne Park with "coaching pods" at court level in the corners of the main stadiums.

Novak Djokovic made a slice of Grand Slam history on his way into the Australian Open third round on Wednesday but last year's women's finalist Zheng Qinwen was knocked out in the biggest shock so far.

The Spanish third seed showed no mercy to Japan's Yoshihito Nishioka, who was taught a 6-0, 6-1, 6-4 lesson on Margaret Court Arena in an 81-minute rout.

The normally ice cool "Queen Wen" got hot under the collar as she was sent packing 7-6 (7/3), 6-3 in the second round by world number 97 Laura Siegemund of Germany.

It was a winning start for Bangladesh in the inaugural edition of the Kho Kho World Cup as country’s men’s and the women’s teams won their respective fixtures in New Delhi on Tuesday.

The feisty Russian, a three-time finalist in Melbourne, lost his cool in the third set before rallying to beat unheralded Thai Kasidit Samrej 6-2, 4-6, 3-6, 6-1, 6-2 on Rod Laver Arena.

The sixth seed from Kazakhstan demonstrated her pedigree as she manoeuvred the 16-year-old world junior number one from Australia to all parts of Margaret Court Arena.

The world number four wasted little energy to swat aside Jenson Brooksby, who is on the way back from a doping suspension, 6-2, 6-0, 6-3 on John Cain Arena.

According to French online media outlet La Lettre, "more than 100 defective medals have been returned by disgruntled athletes", who have seen their awards deteriorate.

So far, none of the more than 80 venues due to stage Olympic competition in Los Angeles have been directly affected by the infernos that have left at least 24 people dead and reduced entire neighborhoods to smouldering ruins.

Born in Japan, the 27-year-old has lived in the U.S. since childhood and has made LA her home.

"I'm going to make this short and sweet," the British fighter said in a social media post. "I'd like to announce my retirement from boxing.

In-form Gauff laid down a marker as she swept aside former champion and fellow American Sofia Kenin in straight sets on Rod Laver Arena.

Cricket will be making its first-ever appearance at the Summer Games in over a century at Los Angeles 2028.

Novak Djokovic has revealed a new secret weapon that he credits with helping keep him healthy and prolong his career -- a green "energetic disc".

Thunder and lightning saw players and fans rushing for cover, with the heavy rain a headache for organisers who face a match backlog.