Tennis: Andy Murray grinds down Milos Raonic

Andy Murray of Britain celebrates after winning a point against Milos Raonic of Canada during their semifinal match at the Australian Open. Photo / AP.

Andy Murray will have a fourth chance to defeat Novak Djokovic in the Australian Open final after going the distance with Milos Raonic in a gruelling five-set semi-final.

In one of the matches of the tournament, Murray prevailed 4-6 7-6 6-7 (4-7) 6-4 6-2 as the match entered a fifth hour.

Even by his indefatigable standards, Murray was pushed to the brink by the world No.14.

Up two sets to one, a groin injury slowed Raonic as he edged towards a first grand slam final of his career.

The usually stony-faced Canadian thrashed his racquet to the court as he gave up a fifth-set break; his frame ailing and his prospects shot.

But ever more the praise to Murray, who triumphed in a battle of wills, endurance and serves.

Murray said getting a read on his opponent's serve was key to staying in the match. "It was tough," he said.

"It was frustrating when you don't have much say in the points."

"But he definitely slowed down ... it would have been nice to play a competitive fifth set."

The almost metronomic rhythm of games won on serve produced a hypnotic effect, snapping the capacity Rod Laver Arena crowd to action whenever a break loomed.

In the first three hours, Murray and Raonic combined to produced just nine break points between them.

For all of the talk of Raonic's super serve, Murray's action proved just as effective.

The Canadian might have won the ace count 23-9 but a greater share of the Scot's serves didn't come back over the net.

The most unusual game of the night was the first; with Murray broken to love.

With Raonic's serve peaking at 233km/h, the Canadian held firm to edge a tight opening stanza. Murray stayed calm.

The world No.2 knuckled down, hitting just five unforced errors as he claimed marathon second set 7-5.

From 4-4 and 15-30 down, Murray raised his serve to a new level, winning 19 straight points with the ball in hand.

Raonic followed suit, renewing his baseline effort and upping his serve once more. An untouchable Raonic ace down the tee sealed a third set tiebreak.

The world No.14 headed down the tunnel early in the fourth set to treat his groin, but returned with intent.

With Raonic serving first, Murray's service became perilous; chances for Raonic grab a crucial break and run into the final.

Instead it was Murray who snapped the 13th seed's service, roaring as he stared down three break points and force a fifth set.

The fourth set proved decisive.

Raonic kept his effort to the end but could no longer compete as Murray raged into his fifth Melbourne Park final.

The 28-year-old was defeated in 2010 by Roger Federer and has fallen victim to Novak Djokovic in three of the last five Melbourne Park deciders.

The second seed's win also secured a slice of history for his family.

With brother Jamie to contest Saturday's doubles final, the pair are the first brothers to reach finals in the singles and doubles events at a major tournament in the Open era.

-AAP