Adelaide United defeated reigning A-League Champion Newcastle United while Wellington Pheonix upset Sydney FC and underdogs Queensland Roar scored a valuable away win over Melbourne Victory.

Late goals to Queensland Roar substitutes Tahj Minniecon and Michael Zullo have sealed a deserved 2-0 upset over A-League leaders Melbourne Victory, who had a player sent off for the third successive match.

Minniecon finally managed to hit the target in the 83rd minute and Zullo in injury time after wasteful Roar had squandered a succession of chances to inflict Victory's first defeat of the season.

Victory midfielder Carlos Hernandez was sent off for two yellow card offences in the space of 10 minutes in the second half, referee Ben Williams giving him his marching orders for diving in the 57th minute.

It is the third successive match Melbourne have finished with 10 men, following a win over Adelaide United and a draw with Central Coast which also featured red cards.

Victory and Sydney FC now share the top of the A-League despite Sydney's shock 2-1 loss to Wellington Phoenix in Wellington earlier on Sunday.

Wellington Phoenix have jumped off the bottom of the A-League ladder after an upset 2-1 victory over previously unbeaten Sydney FC 2-1 at Westpac Stadium on Sunday.

In front of an increasingly delirious home crowd in Wellington, the Phoenix finally rediscovered goalscoring form to record their first win of the season.

With the scores tied 1-1 at the break, the Phoenix reaped the reward for some uncompromising defence and enterprising midfield play when Tim Brown planted home the winner after 76 minutes.

Brazilian striker Cristiano notched a second-half double as Adelaide United wore down 10-man Newcastle Jets to win 2-0 at Hindmarsh Stadium.

Central Coast Mariners have charged into third spot on the A-League ladder with a commanding 4-1 win over Perth Glory on Friday night.

AAP

A-League Table after Round 6