Steph Catley ensured co-hosts Australia opened their World Cup campaign with a 1-0 victory over the Republic of Ireland despite the absence of star striker Sam Kerr.

Catley’s second-half penalty was enough to clinch three points for the Matildas in front of a record crowd of 75,784 at Stadium Australia in Sydney.

However, they had to do it the hard way after their record goalscorer Kerr was ruled out of the first two Group B games with a calf injury suffered in training.

Vera Pauw’s side, making their debut at a major tournament, made life difficult throughout for a side ranked 10th by FIFA, 12 places above Ireland.

But despite a late flurry, they were unable to get themselves back on level terms and will now turn their attention to next Wednesday’s clash with Canada in Perth.

For Australia, there was relief after three hard-earned points were banked to match the feat of co-hosts New Zealand, who had earlier stunned Group A rivals Norway with a 1-0 victory in Auckland, ahead of their second fixture against Nigeria next Thursday.