Melbourne, Jan 21 (IANS): Roger Federer, Rafael Nadal and Andy Murray advanced to the third round in the singles competition, while Maria Sharapova also won her women singles' second round match of the Australian Open at the Melbourne Park here Wednesday.

World No.2 Federer dropped a set but beat Italy's Simone Bolelli 3-6, 6-3, 6-2, 6-2 despite being hampered by a mystery problem on his finger at the Rod Laver Arena as Spain's Nadal drew on all of his fighting qualities to beat World No.112 Tim Smyczek 6-2, 3-6, 7-6(2), 6-3, 7-5.

It was believed that 17-time Grand Slam champion Federer was stung by a bee which forced the four-time Australian Open champion to receive medical treatment after losing the first set.

The Swiss himself was unsure what happened but said he also believed he was stung by a bee.

"I don't know what that thing is. It's the weirdest thing. I don't know. I feel it on the tip of my finger. Just felt really odd starting after the break, and for three, four games, it was the funniest feeling I have. I feel like it's numb and swollen," he explained after winning.

But the right-hander overcame the discomfort to win in two hours and nine minutes smashing 36 winners and compelling his opponent to commit 39 unforced errors.

Nadal, playing just his 10th tour-level match since July 2014, ground out a comeback victory to maintain his record of never losing to a qualifier at a Grand Slam championship.

The 2009 champion triumphed in four hours and 12 minutes to set up a third round meeting against Dudi Sela, who defeated No.28 seed Lukas Rosol 7-6(2), 5-7, 7-5, 6-3.

Nadal's backhand did the damage in the 31-minute opener, as he broke Smyczek in the fourth and eighth games. But Smyczek kept battling and was gifted a 4-3 lead in the second set, courtesy of a double fault at 0-40.

The American, playing just his 14th major championship match, won five straight games to take a 2-0 lead in the third set. But Nadal bounced back. Smyczek grew in confidence, with two stunning groundstroke winners giving him a 5-2 lead in the tie-break. He closed out with an ace.

Nadal regained his composure to break Smyczek for a 4-2 lead in the fourth set, when guile and court craft took him into a decider. In a tense fifth set, Nadal broke Smyczek to 15 for a 6-5 lead. Having led 40-0, Nadal secured the win on his fourth match point opportunity.

No.6 seed Murray showed imperious form in overpowering Australia's Marinko Matosevic 6-1, 6-3, 6-2, making just 12 unforced errors.

The Briton, 27, won in one hour and 42 minutes under sweltering heat conditions at the Margaret Court Arena. He will play Portugal's Joao Sousa in the last 32 stage.

Murray said he recognised early in the proceedings that his opponent was not in his elements and played with a lot of variety to make it difficult for him.

World NO.2 Sharapova had a narrow escape in the second round against qualifier and fellow Russian Alexandra Panova, before winning 6-1, 4-6, 7-5.

The No.2 seed was in complete control as she broke service to take the first set 6-1, in just 26 minutes, on centre court at the Rod Laver Arena.

But Panova broke in the first game of the second set and soon took a 2-0 lead. She broke again before eventually holding serve to take it 6-4.

Sharapova immediately lost serve at the start of the third set, and with the double faults and unforced errors mounting, she found herself trailing 1-4.

However, the 2008 Australian Open champion dug deep, saving two match points at 4-5 in the third to ultimately clinch a narrow victory.