MELBOURNE, Jan. 17 -- Many of the top seeds at the Australian Open struggled through their second round matches on Wednesday, as the tournament's young guns put on a show for the 70,000 fans in attendance at Melbourne Park.

What was supposed to be a routine match up for second seed Caroline Wozniacki, soon turned into the most exciting tussle of the day.

Down one set to 19-year-old Croatian Jana Fett, Wozniacki looked like she would be making an early exit in the tournament.

With clear signs of frustration, including a moment when the Danish star threw her racket on the ground in anger, Wozniacki managed to compose herself and survive multiple match points in the third set to break serve three times and eventually get the win 6-3, 2-6, 5-7.

It was a similar story for Jo-Wilfried Tsonga, who was pushed to the limit in a 5-set thriller by 18-year-old Canadian player, Denis Shapovalov.

In the end, the experienced Frenchman hung on to win the battle 6-3, 3-6, 6-1, 6-7 (4-7), 7-5.

Third seed Grigor Dimitrov also had a grueling 5-set encounter with 22 years old American Mackenzie McDonald.

But the Bulgarian managed to clinch the victory 4-6, 6-2, 6-4, 0-6, 8-6, after looking down and out in the fourth set.

Other top contenders like Rafael Nadal, Marin Cilic and Pablo Busta Carreno managed to cruise through their second round clashes, while crowd favorite Nick Kyrgios found things a little more difficult.

There was certainly no problem with the way the Aussie was playing, taking out the contest in four sets.

The issues came with a bizarre series of disruptions off-court, that saw a helicopter halt play, a heckler in the crowd get ejected from the venue after shouting and a problem with the arena's audio speakers that caused feedback issues for both players.

"The guy in the crowd was crazy," Kyrgios said.

"I didn't really know what was going on. [With] the helicopter, that's when I was thinking like, of course it's at my match...there were a lot of things going on there today," he explained after the match.

In the women's bracket, fourth seed Elina Svitolina eased her way to the third round, while world number 7 Jelena Ostapenko was too strong for China's Duan Yingying.

Belinda Bencic crashed out against her little-known Thai opponent Luksika Kumkhum, just 48 hours after defeating last year's finalist Venus Williams, in straight sets.

Frenchwoman Alize Cornet shocked Germany's Julia Goerges in straight sets, while China's 25th seed in the tournament Zhang Shuai bowed out to the Czech Republic's Denisa Allertova in an entertaining back and forth battle.

But the story of the day belonged to 15-year old Ukrainian Marta Olehivna Kostyuk, who became the youngest women to make it into the third round of a Grand Slam in over 20 years, after beating out home town hero Olivia Rogowska.

MELBOURNE, Jan. 17 -- Many of the top seeds at the Australian Open struggled through their second round matches on Wednesday, as the tournament's young guns put on a show for the 70,000 fans in attendance at Melbourne Park.

What was supposed to be a routine match up for second seed Caroline Wozniacki, soon turned into the most exciting tussle of the day.

Down one set to 19-year-old Croatian Jana Fett, Wozniacki looked like she would be making an early exit in the tournament.

With clear signs of frustration, including a moment when the Danish star threw her racket on the ground in anger, Wozniacki managed to compose herself and survive multiple match points in the third set to break serve three times and eventually get the win 6-3, 2-6, 5-7.

It was a similar story for Jo-Wilfried Tsonga, who was pushed to the limit in a 5-set thriller by 18-year-old Canadian player, Denis Shapovalov.

In the end, the experienced Frenchman hung on to win the battle 6-3, 3-6, 6-1, 6-7 (4-7), 7-5.

Third seed Grigor Dimitrov also had a grueling 5-set encounter with 22 years old American Mackenzie McDonald.

But the Bulgarian managed to clinch the victory 4-6, 6-2, 6-4, 0-6, 8-6, after looking down and out in the fourth set.

Other top contenders like Rafael Nadal, Marin Cilic and Pablo Busta Carreno managed to cruise through their second round clashes, while crowd favorite Nick Kyrgios found things a little more difficult.

There was certainly no problem with the way the Aussie was playing, taking out the contest in four sets.

The issues came with a bizarre series of disruptions off-court, that saw a helicopter halt play, a heckler in the crowd get ejected from the venue after shouting and a problem with the arena's audio speakers that caused feedback issues for both players.

"The guy in the crowd was crazy," Kyrgios said.

"I didn't really know what was going on. [With] the helicopter, that's when I was thinking like, of course it's at my match...there were a lot of things going on there today," he explained after the match.

In the women's bracket, fourth seed Elina Svitolina eased her way to the third round, while world number 7 Jelena Ostapenko was too strong for China's Duan Yingying.

Belinda Bencic crashed out against her little-known Thai opponent Luksika Kumkhum, just 48 hours after defeating last year's finalist Venus Williams, in straight sets.

Frenchwoman Alize Cornet shocked Germany's Julia Goerges in straight sets, while China's 25th seed in the tournament Zhang Shuai bowed out to the Czech Republic's Denisa Allertova in an entertaining back and forth battle.

But the story of the day belonged to 15-year old Ukrainian Marta Olehivna Kostyuk, who became the youngest women to make it into the third round of a Grand Slam in over 20 years, after beating out home town hero Olivia Rogowska.