Brisbane, Australia, 6 January 2012 | AAP

Australian No.1 Bernard Tomic is through to his maiden ATP semifinal after posting a straight-sets win over Denis Istomin at the Brisbane International on Friday.

But the 19-year-old hardly appeared satisfied with his milestone as he booked a dream showdown with top seed Andy Murray.

Tomic’s countdown to the year’s first grand slam gained ominous momentum when he downed Uzbek Istomin 6-3 7-6 (7-4) in their quarter-final.

Tomic’s rapid rise was put in perspective when he arrived at the Brisbane International as the eighth seed and world No.42.

Last year he relied on a wildcard to play due to his No.208 ranking.

Now Tomic looks set to soar to a career-high ranking in the 30s following his stellar run in Brisbane – and he could even gain a prized Australian Open seeding if he wins the tournament.

But the true gauge awaits on Saturday – world No.4 Murray, who earlier cruised into the semifinals with a 6-2 6-2 thumping of doubles partner Marcos Baghdatis.

Tomic – the youngest player in the men’s top 50 – had never progressed past the Brisbane International first round in three previous attempts.

But on Friday the Wimbledon quarterfinalist would have been forgiven for backing himself to at least make the final of his home tournament after finally providing Istomin a hit-out.

Remarkably, Istomin, 25, came into the quarter-finals without completing a match.

Florian Mayer had retired with a groin injury in the second set of their opening match and another German – veteran Tommy Haas – withdrew with a calf strain to give him a round-two walkover.

Tomic looked like a young man in a hurry from the outset, breaking Istomin in the fourth game to seal the first set in 31 minutes.

He had the crowd on its feet when he outlasted Istomin 7-4 in the tiebreaker to seal the match in 78 minutes.

French second seed Gilles Simon was the first man through to the last four when he eliminating Santiago Giraldo 7-6 (7-2) 6-4 on Thursday.

Simon will next take on Ukraine’s world No.15 Alexandr Dolgopolov after the third seed outlasted former champion Radek Stepanek, the sixth-seeded Czech, in their quarterfinal 4-6 6-3 6-3.