The 2.08-metre qualifier, who made Wimbledon history by dispatching defending champion Lleyton Hewitt in the first round on Monday, earned the applause of a tightly packed crowd squashed on to benches round court number 14.

His earlier triumph had taken centre stage on Centre Court in front of the royal box and been beamed to screens round the world. On Wednesday spectators had to balance on dustbins behind the hand-scoreboard for a glimpse of the giant-killer.

But Karlovic, apparently unfazed, used much the same tactics against Baccanello, also a qualifier ranked 204 in the world, as he had against the number one seed.

He thumped down 29 aces in the two hour 35 minute match and had his opponent squawking in frustration as serve upon unreturnable serve pinged skywards off Baccanello's racket frame.

Karlovic, whose sudden fame -- and unexpected wage packet -- allowed him to move this week to a swanky hotel, began the match with an ace and won the first set with an ace.

Baccanello, buoyed by raucous support from a handful of compatriots yelling "Aussie, Aussie, Aussie," managed to find a way through the barrage only in the third set when the Croatian, who says his biggest problem is moving and bending on court, began to tire.

But he found a second wind in the fourth, earning a third-round spot in his first Grand Slam tournament.

Hewitt was the first defending Wimbledon champion since tennis went professional in 1968 to lose in the first round.