Carlos Alcaraz given fright by Lorenzo Sonego before closing out ...

Carlos Alcaraz came under fierce scrutiny before prevailing against Lorenzo Sonego in the Australian Open second round, with both players producing moments of magic on Rod Laver Arena.

The Spaniard faltered in a second set tie-break and was pegged back in an epic fourth before finally advancing 6-4 6-7(3) 6-3 7-6(3) on Rod Laver Arena.

It was Alcaraz's 200th match on tour and he next faces wildcard Juncheng Shang.

"I'm really happy with my performance today. I think both of us played at such a great level, high intensity," said Alcaraz.

"The match was tricky with the wind and sun. It was tough to play your best.

"We tried to stay there all the time, even if I lost the second set. I played a good game. It was a great match."

Alcaraz looked unsettled in the early stages as Sonego came out firing, with the Italian coming up good when break point down as the world No. 2 struggled to make the early breakthrough.

After missing opportunities at 1-1 and 2-2, Alcaraz finally struck at 3-3 to take control of the opening set, going on to comfortably serve it out as a routine win looked on the cards.

Sonego ripped into a 5-1 lead in the breaker with a double mini break and after a brief wobble, was soon lapping up the applause for levelling the match.

Alcaraz looks best placed of the current generation to emulate the 'Big Three' of Novak Djokovic, Rafael Nadal and Roger Federer, a trio who know how to hit back immediately after a setback, and the Spaniard did just that as broke straight away in the third set.

The 20-year-old sailed through the rest of the set on serve to regain the lead, with one colossal forehand branded "unnecessarily powerful" by Eurosport commentator Naomi Cavaday.

The match looked like it was finally slipping away from Sonego when he began the fourth set how he started the third by being broken.

But this time, he mounted a response. The Italian let out a roar after pouncing on his first break opportunity of the match, then cranked up the decibels again when he delivered a strong hold in the next.

After a topsy-turvy match, both players were now in full flow and when Sonego snuffed out an audacious Alcaraz tweener with an even better drop shot volley, the players grinned and slapped hands at the net.

A high-quality set peaked at 5-5 when a wildly ambitious – and ultimately successful – between-the-legs shot from Sonego was trumped a point later by Alcaraz crashing a sensational winner from deep out wide that almost skimmed the umpire's chair.

It was fitting that the fourth set went to a tie-break, with Alcaraz stepping up his intensity as he finally forced Sonego to crack.

The Spaniard sealed victory with a wicked smash for his 200th win on tour.

"I’m really happy. Two-and-a-half years and already 200 matches on the tour. It’s incredible. I’m looking forward to making 300. I hope to make it soon," added Alcaraz.