A-League champions Melbourne City threw a two-goal lead away to draw 2-2 away at Adelaide United in their second game of the season.

City kicked their title defence off with a 2-1 win over Brisbane Roar in their opening match and looked set to make it two wins from two after goals from Jamie Maclaren and Andrew Nabbout gave them a 2-0 advantage after 61 minutes.

However, Adelaide struck twice in the closing stages, with Stefan Mauk halving the deficit before Ben Halloran grabbed a dramatic 90th-minute equaliser to stun City.

Elsewhere on Saturday, Sydney, who finished just two points behind City in second last season, slipped to a 1-0 defeat against Macarthur at home after an early Lachlan Rose strike.

Macarthur are now level on points with table-topping City and Wellington Phoenix, who beat Central Coast Mariners 2-1, but are behind the pair on goals scored and sit third.

Gary Hooper scored for the second game running for the Phoenix in their home clash with the Mariners, who pulled one back through Marco Urena before Jaushua Sotirio fired in the winner.

The Nix are now unbeaten in 13 matches stretching back into last season and face Western Sydney Wanderers in their next game.