Auckland FC have claimed a 1-0 win over Macarthur FC in Unite Round to remain undefeated and take top spot on the A-League Men table.

Playing in their first game in Australia, the expansion club extended their winning streak to four matches when Guillermo May scored in the 34th minute at Allianz Stadium today.

Two points clear of the pack, Auckland are the only team to have won all their fixtures.

Making the feat more impressive, Steve Corica's 'Black Knights' have also kept a clean sheet across the opening five rounds.

The Bulls remain seventh after their third loss, sitting outside the top six by three points.

Macarthur left-back Walter Scott paid the price for a poor pass in Auckland's attacking half, opening the door for May to score in the first half.

Scott had intended for captain Valere Germain to receive the ball but Kiwi defender Francis De Vries intercepted to hand off to Liam Gillion and start the chain for their goal.

Kealey Adamson almost levelled the scores in the 67th minute but his long-range attempt went wide.

Ariath Piol who nailed a stunning bicycle kick goal in the Bulls' 2-1 win against Sydney FC last round, tried his luck two minutes later but was denied by goalkeeper Alex Paulsen.

Macarthur enjoyed early dominance and were cheered on by a union of Bulls fans and Wellington faithful who stayed back from the previous fixture.

Piol had sounded a warning after earning a starting position in the Bulls line-up, flaunting his pace to easily outrun defender Dan Hall and unleash towards goal.

Had it not been for an impeccable save by Paulsen, Piol would have opened the scoring in the 17th minute.

Germain missed a chance to break the deadlock after a superb cross from Scott, his header just off target in the 24th minute.