Melbourne VIC, Australia, 21 January 2015 | AAP

Bernard Tomic has staged a spirited fightback to send local hopes soaring at the Australian Open at Melbourne Park.

Tomic roared back from a set and a break down to upend German 23rd seed Philipp Kohlschreiber 6-7 (5-7) 6-4 7-6 (8-6) 7-6 (7-5) to complete a thrilling Wednesday night hat-trick for Australia.

The grand slam hosts are now assured of second-week singles participation after Tomic’s fighting win set up an all-Australian third-round shootout with supersonic server Sam Groth.

“We’re not going to have a lot of rallies, are we,” Tomic said.

Teenage excitement machine Nick Kyrgios is a hot favourite to follow Tomic or Groth into the last 16 after withstanding 40 aces from Ivo Karlovic to cut down the giant No.23 seed 7-6 (7-4) 6-4 5-7 6-4 in a cool and composed display on Show Court 3.

If Kyrgios can see off Tunisia’s world No.75 Malek Jaziri on Friday, the 19-year-old will likely take on Roger Federer in a blockbuster battle for a quarter-final spot.

Tomic’s tournament appeared to be coming to an end when he dropped the opening set in a tiebreaker and trailed Kohlschreiber 3-1 in the second set.

But, unlike his first-round mid-round stoppage against Rafael Nadal last year, Tomic refused to quit.

Even after recovering to take the second set to draw level, the 22-year-old repeatedly found himself under pressure.

Time and again he stared down break points and, at one stage in the pivotal third-set tiebreaker, even three set points.

Seemingly on each occasion, Tomic’s clutch serving saved him.

He racked up 23 aces in all.

If not his serve, Tomic’s big, flat forehand came to the rescue in the pressure moments as he eventually prevailed after three hours and five minutes.

“It was very difficult. He was playing very well,” Tomic said.

“I had to find a way to get out of it. He was destroying me.

“I had to dig deep.”