A slice of the Spaniard-Australian's magic interrupted an otherwise dour match in Gosford, the United midfielder springing upon a lacklustre clearance to hammer an inch-perfect volley into the left corner.

Adelaide dictated the tempo and dominated possession for the entire match, with Alen Stajcic clearly intent on retaining a counter-attacking philosophy, even when behind at home. 

In a rare moment of forward-pressure, Jem Karacan scythed down Isaias and earned a second yellow card for his efforts, all but ending the contest.

The game then uneventfully wound to a close, allowing United to leapfrog Melbourne City into fifth while delivering a much-needed eight point buffer over Newcastle Jets in seventh.

"We haven't played our best football tonight but the three points were most important," Isaias said. "I'm really happy to help the team score goals. 

"We all are professionals, so is (Kurz) as a coach, we want to win every game and everyone is doing their job."

Tom Hiariej was equally positive about his team's performance, despite their insipidness going forward.

"When they've got the ball, we're very well organised," he noted.

"We knew what to do and from here we need to play a little more football, but the coach has been here for two weeks. (Stajcic) is a little more structured defensively, so we build from here.

"Today we were very positive, but we have to be calmer on the ball and provide more in the front third."