* Swiss marches on in bid for fifth title
* Tomic briefly threatens in second set
* Federer to meet Raonic in fourth round (Adds quotes, details)
By Ian Ransom
MELBOURNE, Jan 19 (Reuters) - Roger Federer humbled local favourite Bernard Tomic 6-4 7-6 6-1 to sail into the last 16 of the Australian Open and then apologised to a packed centre court crowd for "beating up" on the home players.
Saturday's anticipated clash between master and apprentice briefly caught fire in the middle stages but fizzled out as the Swiss dispatched the last Australian from the tournament.
The outcome was a repeat of Federer's straight-sets victory over Tomic in the fourth round last year, and came three years after he ousted Australia's former world number one Lleyton Hewitt at the same stage.
"It's nice that you guys invite me back every year," Federer told a crowd of 15,000 under the lights at Rod Laver Arena after beating the vaunted 20-year-old in a tick under two hours.
"It's not my favourite part of the job, beating up on the home heroes."
The bad boy of tennis Down Under had raised the stakes in the leadup, declaring himself confident of upsetting the 17-times grand slam champion.
But he later conceded he was spooked before a point was played, when his opponent's achievements were listed over the loudspeaker.
"I tried to block out who's on the other side of the net but couldn't quite do it after that announcement," said the 43rd-ranked Tomic, who in the opening game lost his serve for the first time at Melbourne Park.
Though Tomic composed himself and went toe-to-toe with the Swiss, the break was enough for Federer to secure the first set.
The Australian pushed hard to take the second to a tiebreaker and came within two points of levelling the match, but was demoralised as Federer wrenched back the momentum with a brilliant counter-attack.
Clawing back from 5-3 down in the tiebreaker, Federer returned Tomic's forehand rockets with interest and the pressure finally told when the Australian floated a backhand past the baseline.
The atmosphere in the stadium until that point had been akin to a soccer game, but it petered out as Federer roared to a 3-0 lead in the third set.
Federer closed out the match with a monster serve to set up an encounter with another young pretender, 13th-seeded Canadian Milos Raonic.
"I've had some tough matches with him in the past. All of them went the distance," Federer, who is bidding for a fifth title at Melbourne Park, said of Raonic, the big-serving 22-year-old.
"You always feel, especially after an off-season like the one we've just had, he's maybe improved again a few things or he's worked on a few things.
"So you would expect maybe some more unexpected stuff that he didn't do last time around. We'll see how it goes. I'm excited about the match anyhow."
(Editing by Patrick Johnston and Stephen Wood)