Melbourne, Australia, 16 January 2012 | AAP

Rising star Bernard Tomic has staged a mighty comeback to charge into the second round of the Australian Open at Melbourne Park.

The boom teenager defied soaring mercury to rally from two sets to love down to oust Spanish ironman and 2009 semifinalist Fernando Verdasco 4-6 6-7 (7-3) 6-4 6-2 7-5 in four hours and 11 minutes.

Tomic’s reward for winning his longest-ever match is a clash on Wednesday with American Sam Querrey and a possible fourth-round showdown with 16-times grand slam champion Roger Federer.

The Kooyong Classic winner didn’t quite continue on from where he left at the weekend as he dropped the opening two sets to be staring down the barrel.

But defying the odds and temperatures in the mid-30s, Tomic ran down his more-experienced foe who famously pushed Rafael Nadal to five hours and five sets in the Open semis three years ago.

Despite falling behind, Tomic, ranked 38th, started brightly enough against the world No.24, holding his opening service game to love and conjuring the first break points of the match in the eighth game.

Verdasco, though, survived three break points in an 11-minute game to hold for 4-4 before Tomic lost serve the very next game.

The Spaniard didn’t need a second invitation to serve out the set after 45 minutes.

Tomic quickly regrouped and went up 2-0 when Verdasco struck a backhand long to drop his opening serve of the second set.

The 19-year-old gifted the break straight back with a flurry of unforced errors, including his first double-fault.

There was drama in the following game when Verdasco took offence to being warned by chair umpire Pascal Maria for coaching.

Maria claimed Verdasco’s support cast were “talking too much”, prompting the 22nd seed to fire back: `Is vamos (c’mon) after breaking (serve) too much?’

But the exchange proved more of a distraction for Tomic, who carelessly dropped serve again that game to allow Verdasco to go up 3-2.

Tomic broke straight back for 3-3, but squandered a golden opportunity to level the match.

He had three set points with Verdasco serving at love-40 at 5-5, but netted a backhand, failed to return a big serve and then dragged a forehand wide with an open court beckoning.

The Australian’s big opportunity seemingly lost; Tomic surrendered the tiebreak and the writing looked on the wall.

But just as Verdasco appeared set to twist the knife, Tomic wriggled free, reeling off five games in a row to snatch the third set and forge ahead 2-0 with a break in the fourth.

Suddenly the supposedly seasoned Verdasco looked ragged and Tomic had an extra spring in his step.

Despite Verdasco briefly drawing level at 2-2, the Spaniard, applying heat packs at every changeover, continued to struggle in the tough conditions as Tomic forced a fifth and deciding set with two more service breaks.

Verdasco required four aces to hold serve in the opening game of the fifth set and then saved two more break points in the ninth game, but couldn’t deny Tomic in the 11th.

The Spaniard fired a forehand long and Tomic calmly closed out the cliffhanger to raise Australian hopes that he may yet prove himself the real deal.