MELBOURNE: For the second time in three days, Novak Djokovic won a match at the Australian Open and was confronted by questions about match-fixing in the sport.

The five-time champion had just beaten 19-year-old French wild-card entry Quentin Halys 6-1, 6-2, 7-6 (3) in the second round on Wednesday night - his 34th win in his last 35 matches at Melbourne Park - when his news conference veered to questions about the issue that has overshadowed the start of the season's first major.

After his first-round win, on the day when the BBC and BuzzFeed News published reports alleging match-fixing had gone unchecked in tennis, the No. 1-ranked Djokovic recalled when a member of his support team was approached with an offer to throw a match in Russia in 2007.

That approach didn't reach him directly, he said, and was rejected immediately.

After his second-round win, he was asked about an Italian newspaper report casting doubt over his performance in a match against Fabrice Santoro in Paris in 2007.

Djokovic said the speculation was getting out of control.

“What (is there) to say? I've lost that match. I don't know if you're trying to create a story about that match or for that matter any of the matches of the top players losing in the early rounds. I think it's just absurd,” Djokovic said.

“It's not true.

“My response is that there's always going to be, especially these days when there is a lot of speculation - this is now the main story in tennis, in sports world - there's going to be a lot of allegations,” Djokovic said.

“I said everything I needed to say two days ago. Until somebody comes out with the real proof and evidence, it's only a speculation for me.”

Djokovic lost to Santoro 6-3, 6-2 in the second round of the Paris Masters indoor tournament in October 2007. Djokovic, who had two wisdom teeth removed after the Madrid Masters earlier that month, said after the loss to Santoro that he was not fully fit because he was still taking medication.

The BBC and BuzzFeed reports said 16 players had been repeatedly flagged to tennis authorities for suspicious performances, including a Grand Slam winner, and half of them were at this year's Australian Open.

Djokovic has said he didn't believe any elite players were involved. Roger Federer agreed, and said people making the accusations should name names.

Top seeds progress

On Wednesday, Federer extended his streak of reaching the third round at the Australian Open to 17 consecutive years. The four-time Australian Open champion, playing his 65th consecutive major, advanced 6-3, 7-5, 6-1 over Alexandr Dolgopolov. It was Federer's 299th match win at a major.

He lost in the third round in his first two trips to Melbourne Park in 2000 and '01 and again last year - in between he won the title four times and lost one final during a run of reaching the semifinals or better in 11 straight years.

“It's the least I expect to be in the third round of a Slam, obviously, so I'm pumped up, playing well, feeling good,” Federer said.

“But there's always a danger, you know. Like last year the third round was the end for me, so I hope to go further this time.”

Federer will next play Grigor Dimitrov, who beat Marco Trungelliti 6-3, 4-6, 6-2, 7-5.

Jo-Wilfried Tsonga went to the aid of a ball girl in his match, gently helping her off the court in the third set when she became ill before finishing off a 7-5, 6-1, 6-4 win over Omar Jasika.

Other seeded players advancing included No. 6 Tomas Berdych, No. 7 Kei Nishikori and 2014 US Open champion Marin Cilic.

Serena Williams set a record when she played her 79th main draw match at the Australian Open, and beat No. 90-ranked Hsieh Su-wei 6-1, 6-2.

“It all started here. This is where I played my first Grand Slam right on this court and I'm still going, it's such an honor,” said Williams, a six-time champion who has a 70-9 record at Melbourne Park. “I love it every time I come here.”

In the biggest upset of the day, two-time Wimbledon champion and sixth-seeded Petra Kvitova was beaten 6-4, 6-4 by Russian-born Australian Daria Gavrilova.

Williams' next opponent will be 18-year-old Russian Daria Kasatkina, who beat Croatia's Ana Konjuh 6-4, 6-3, and she faces a potential quarterfinal match against 2015 finalist Maria Sharapova, who reached the third round with a 6-2, 6-1 win over Aliaksandra Sasnovich.

No. 13 Roberta Vinci beat Irina Falconi 6-2, 6-3 to advance, and is a potential fourth-round rival for No. 4 Agnieszka Radwanska, who beat Eugenie Bouchard 6-4, 6-2 in a match featuring two former Wimbledon finalists.