Djokovic clobbers Krueger; Zverev, Karlovic, Raonic advance

Top seed Novak Djokovic looked every inch the Australian Open favourite as he comfortably beat American qualifier Mitchell Krueger 6-3 6-2 6-2 to reach the second round on Tuesday.

Soaking up the Rod Laver Arena limelight, the Serb moved superbly in his Melbourne Park opener and hit 42 winners to wrap up the one-sided clash in little more than two hours.

Despite the scoreline, the 230th-ranked Krueger hardly disgraced himself and broke Djokovic in the third game of the first set.

That was as good as it got for the American, as Djokovic coasted to an easy victory. The Serb will continue his bid for a record seventh Australian Open title against Jo-Wilfried Tsonga, the man he beat for the 2008 trophy.

'SCARY' RAONIC BLOWS AWAY KYRGIOS

Canadian Milos Raonic unleashed a "scary" display of ruthless serving to break the hearts of home fans and dismantle an ailing Nick Kyrgios 6-4, 7-6 (7/5), 6-4 on Tuesday.

The Canadian 16th seed blasted into the second round of the Australian Open in 1hr 56min, dropping just 11 points on his own serve against a forlorn Kyrgios, who needed treatment several times on a taped up knee.

"When I got to 3-3, it just flared up," a dejected Kyrgios told the physio during a break at the end of the first set.

"Every time I rock back on my serve I feel it. I did an extended warm-up, I warmed up properly. I don't understand," he complained.

Raonic said he didn't want to comment about his hampered opponent's troubles after producing a near flawless exhibition of precision and power serving.

"I don't want to say too much. It always comes down to a few points here and there," said the former world number three who now faces the 2014 Australian Open champion Stan Wawrinka in a blockbuster second-round clash on Thursday.

"It's always tough against Nick anyways. Now it's on to the next one."

Kyrgios refused to blame the knee after the match.

"It was nothing to do with my loss. He was way too good for me," he said. "I've never seen serving as good as that. Milos played scary."

It is the first time that Kyrgios, who reached the last 16 a year ago, has failed to get past the first round in six appearances at his home Grand Slam.

Raonic has reached one Slam final in 2016 at Wimbledon where he lost to Andy Murray.

Earlier that year he achieved his best Australian Open result by reaching the semi-final, where he also lost to the Scot.

JOLTED ZVEREV OVERPOWERS BEDENE

Alexander Zverev overpowered Aljaz Bedene to win their first round clash at the Australian Open 6-4 6-1 6-4 on Tuesday, although it was not until the German lost an early service game that he was provoked to respond and get his campaign rolling.

The first set meandered until the 198 cm (6.5 ft) Zverev found himself down a break.

The 21-year-old became increasingly animated after losing his serve, and reeled off the next eight games.

Like a prizefighter facing a wilting opponent, Zverev pummelled Bedene for the remainder of the match, free-swinging his way to a straight sets victory.

"I mean, obviously I was a little bit sloppy in the beginning, a little bit sleepy maybe, and the break really was like a wakeup call, you know, that I have to start focusing and start playing from the first match on," Zverev told journalists after the match.

Zverev, known as Sascha, has emerged as the leader of tennis' new generation of men's players, a reputation confirmed late last year by his maiden ATP Finals triumph where he beat Roger Federer and Novak Djokovic in consecutive days.

He will play the winner of an all-French first round match between Jeremy Chardy and Ugo Humbert.

Few players have the arsenal to stay with Zverev who hits hard off both wings, and recorded an average first serve speed of 210 km/h during the match.

He also has a knack for making first serves when he is in trouble in a manner reminiscent of great servers such as Boris Becker, Pete Sampras and Roger Federer.

But he was also susceptible to lapses on Tuesday, which included losing a service game to love in the third set despite otherwise dominating proceedings.

Zverev, who is yet to seriously challenge at a Grand Slam, is being mentored by new coach Ivan Lendl, an eight-time major winner who helped usher in a new tennis era with his relentless, powerful baseline game.

Lendl has been credited with elevating his former pupil Andy Murray to a level where he could start winning Grand Slams.

Zverev said that he hoped the new relationship would bear fruit in Melbourne.

"Things don't just come together after you start working with someone one week or two weeks - it really takes time," Zverev said.

"I hope now it's going to be the period where it really starts showing."

KARLOVIC, 39, DEFIES FATHER TIME TO REACH SECOND ROUND

Bashing 39 aces to match his age, Ivo Karlovic became the oldest man to win a match at the Australian Open in over 40 years as he felled Poland's Hubert Hurkacz, a man 18 years his junior, to reach the second round on Tuesday.

On a sweltering day at Melbourne Park, the towering Croat's 6-7(5) 7-6(5) 7-6(3) 7-6(5) win on Court 19 made him the oldest victor at the tournament since Australian icon Ken Rosewall reached the third round of the 1978 tournament at the age of 44.

World number 73 Karlovic also became the oldest winner at any Grand Slam since a 40-year-old Jimmy Connors beat Jaime Oncins to reach the second round of the 1992 US Open.

Karlovic, whose birthday falls on February 28, will be officially middle-aged next month but said he had no intention of winding down while still fit enough to compete.

"I think I'm healthy so hopefully there will be no injuries," the 6-ft 11-in (2.11 metres) Zagreb man told Reuters at Melbourne Park.

"As long as my ranking is up and I get in to all these tournaments, I don't see any reason I should stop."

The oldest man in the men's singles ahead of 37-year-old double defending champion Roger Federer, Karlovic advanced a day after 31-year-old Andy Murray played possibly his last match at Melbourne Park on Monday.

The former world No 1 Briton has been suffering severe pain in his right hip and said before the tournament that he might have to retire.

Where Murray's all-court, scrambling, defensive game has undoubtedly taken its toll, Karlovic's longevity may be explained in part by his commitment to the now rarely seen art of serve-volley.

Boasting a monster serve and an arm-span that can seem as wide as the court, the Croat keeps points short and sharp.

The style can be picked apart by good passers and the power of modern baseline pounders but it has served former world number 14 Karlovic well in a very respectable career of eight titles.

No rally against Hurkacz exceeded four points and the silver-haired Karlovic sealed the match when the Pole sent an attempted passing shot into the tramlines.

He raised his long arms into the air in triumph as a rowdy smattering of Croatian fans chanted, "Ivo! Ivo! Ivo!"

Why would he want to leave all this, he asked.

"This range of emotions from winning to losing, it's, I don't know, it's different," he said.