Australian champions Brisbane Roar made a losing start to their A-League title defence when they fell 2-1 to Adelaide United at home on Sunday.

A day after Spanish star David Villa's goal-scoring debut for Melbourne City, Roar had a stormy introduction to the new season with Socceroos midfielder Matt McKay sent off.

McKay earned his second yellow card for dissent, leaving Brisbane with 10 men for the final 20 minutes as they searched in vain for an equaliser.

Adelaide, coached by Spaniard Josep Gombau, came from a goal down to win through a strike from Bruce Djite and an own goal from James Donachie either side of half-time.

On Saturday, World Cup-winner Villa rescued a point for Melbourne City with a well-taken goal to grab a 1-1 draw with Sydney FC.

Spain's all-time leading goalscorer showed his class with a superb equaliser 15 minutes after coming on as a second half sub in his first outing in a 10-game loan from New York City.

In other games on Sunday, Irish striker Andy Keogh scored as Perth Glory beat Wellington Phoenix 2-1 in New Zealand.

The Glory, rebuilt under coach Kenny Lowe, were lethal on the counter-attack as they posted just their second win in 12 matches in Wellington since 2007.

Keogh scored with a glancing header from a Mitch Nichols cross in the first half. Michael McGlinchey grabbed an equaliser before Jamie McLaren got the winner four minutes from time.

Western Sydney Wanderers crashed to their heaviest A-League defeat to Melbourne Victory on Friday, a fortnight before their AFC Champions League final with Saudi Arabia's Al Hilal.

Victory smashed Wanderers 4-1, with their first three goals coming in the opening 28 minutes against a flat-footed Western Sydney defence.