Sydney, Australia, 11 January 2013 | AAP

Bernard Tomic’s new-found steel has helped the reformed youngster to within one tantalising victory of his maiden ATP Tour final at the Sydney International.

Tomic battled back doggedly from a set down to beat defending champion Jarkko Nieminen 6-7(6) 6-4 6-2 to reach his first semifinal since falling to Andy Murray last January in Brisbane.

The 20-year-old will take on Italian third seed Andreas Seppi, one of his three victims at last week’s Hopman Cup in Perth, for a place in Saturday’s twilight final at Olympic Park.

“I’m ready to go for tomorrow’s semifinal. I’m really confident,” Tomic said.

“I’m going to do everything I can to win. To get the chance to play my first tour-event final and to do it in Australia is going to be unbelievable.”

Despite being below his best against the crafty left-handed Nieminen, Tomic will be a warm favourite to progress to the title match with a seventh straight win this summer.

As it is, the 2011 Wimbledon quarterfinalist now boasts 17 victories from his past 19 matches in Australia, an imposing record ahead of his home grand slam beginning in Melbourne on Monday.

But his latest triumph was hard-earned.

“I was happy with myself to stay in there,” Tomic said.

“Early in that second set, I felt like he was going for shots and was relaxing and for me to stay in there til that 3-all point was really big.

“After I won that second set, I freed up and played better tennis.”

Tomic fought hard to recover from 5-2 down in the opening set, only to blow his own 5-2 advantage in the tiebreaker.

He had two set points at 6-4 and wasted his best chance on his own service when he overcooked a routine forehand.

Heartened by the reprieve, Nieminen continued to attack and was rewarded with the first set.

“I was very concerned after that first set,” Tomic said.

Living on the edge, Tomic grabbed the sole break of the second set late on when Nieminen faltered trying to stay in it at 4-5 down.

The Finn’s poor service game ended quickly when he put two balls in the net to allow Tomic back on level terms.

Despite his experience, Nieminen has has converted only two of his 12 finals into titles and it showed as the left-hander capitulated in the deciding set.

He surrendered his second service game of the set and, rather embarrassingly, the one-time world No.13 shanked his second serve on match point.

Earlier, big-serving South African Kevin Anderson and Frenchman Julien Benneteau, last year’s runner-up to Nieminen, booked their places in Friday’s semifinals.

Anderson downed Uzbek Denis Istomin 6-4 6-3, while Benneteau eliminated American qualifier Ryan Harrison 6-4 6-2.