Melbourne – In-form fourth seed Agnieszka Radwanska overcame tough first set resistance from local qualifier Bojana Bobusic to book her place in the second round of the Australian Open Monday.

The Pole, who won lead-up events in Auckland and Sydney, was pushed hard in the first set before winning 7-5, 6-0 in 79 minutes and will next face either Arantxa Rus of the Netherlands or Romania's Irina-Camelia Begu.

Radwanska came into the tournament as the hottest women's player on tour but her nine straight match wins ahead of the clash with little-known Bobusic seemed to have taken their toll, with a see-sawing first set.

The world number four, who has made the quarter-finals at Melbourne three times but never gone further, was broken in her opening service game as she struggled to find her feet on the Margaret Court Arena.

She fought back to break the feisty Bobusic to make it 1-1 but the Pole was broken again in the fifth game to put the pressure on.

Radwanska rallied against a boisterous home crowd to break back again and eventually take the set 7-5 with a backhand winner off a weak Bobusic second serve.

The effort of the first set took its toll on the Australian who collapsed in the second set, failing to win another game as Radwanska, a Wimbledon finalist last year, stamped her class on the match. —Sapa-AFP