* Berdych reaches first Australian Open semi
* Ferrer shoves linesman (Adds new quotes, details)
By Ian Ransom
MELBOURNE, Jan 21 (Reuters) - Big-serving Czech Tomas Berdych fended off a belated challenge from baseline hustler David Ferrer to reach his maiden Australian Open semi-final on Tuesday with a gritty 6-1 6-4 2-6 6-4 victory.
The rangy seventh seed cruised to a two-set lead over a surprisingly listless Ferrer but spontaneously collapsed in the third set under pressure from the dogged Spaniard.
Ferrer appeared primed to drag the match into an epic struggle but lost focus at 2-2 in the fourth set to surrender serve with a string of unforced errors.
Berdych grimly held onto the advantage, surviving a breakpoint when serving for the match, to seal a semi-final with either triple defending champion Novak Djokovic or eighth seed Stanislas Wawrinka.
Berdych has long chipped away at the dominance of the 'Big Four' of men's tennis, and reached the final at Wimbledon in 2010, but his victory over Ferrer was his first on centre court in Melbourne, where he has generally been relegated to the second show-court in Hisense Arena.
"That's how the setup is. Really, I'm not complaining at all," the 28-year-old told reporters, having made the semi-finals in his 11th appearance at Melbourne Park.
"Both are great arenas with great crowds. The important (thing) is to keep winning, and finally I have a first scalp here, as well."
A baseline pounder with a ferocious forehand, the low-profile Czech has now earned another headline appearance in Rod Laver Arena and believes he is playing some of the best tennis of his career.
Asked whether that's enough to beat Djokovic or the in-form Wawrinka, Berdych was cautious.
"If I'm going to face Novak or Stan, it's going to be, again, about that match," he said. "I'm going to give 100 percent in that match and I'm really not looking into the future."
Berdych's start against Ferrer would have impressed any of the 'Big Four', however, as he mowed through the first set in half an hour, breaking the third seed twice and sealing it with a crunching second serve that the Spaniard could only bash wide.
Ferrer rallied in the second set but was broken again at 4-4 when Berdych ripped a fierce backhand down the line before serving out the set with an ace.
Unbowed, Ferrer galvanised himself to grind Berdych down and saved a string of break points to hold serve in a marathon game at 2-2.
Fired up, he lightly shoved a linesman out of the way of his box to dump his towel, then roared through the next four games as a suddenly nerve-struck Berdych imploded in a hail of unforced errors.
"It was a nervous moment, but nothing," Ferrer told reporters of his brush with the linesman. "I say to him 'excuse me' after that. Nothing special."
Berdych left the court between the third and fourth sets to compose himself and emerged to survive a string of breakpoints in an epic service game at 2-2.
But having dominated play, it was Ferrer who inexplicably lost focus as he slapped a forehand into the tramlines to concede a break in the next game.
Berdych grabbed his chance with both hands and though repeatedly taken to deuce on serve, the Czech saved a breakpoint with a blistering forehand winner and closed out the match after just over three hours with another huge serve.
Berdych has now made the semi-finals of all four grand slams, only the second Czech after Ivan Lendl in the professional era.
"That was definitely the thing which was on my agenda," Berdych said.
"I earned another big bag of experience in the last season. I hope it's going to be helpful for the season. So far everything is going well." (Editing by Patrick Johnston)