Nikola Mileusnic scored two for Adelaide, with Riley McGree also putting his name on the scoreboard.

In his 200th A-League game, Western United's Besart Berisha snatched a double, with Alessandro Diamanti adding a superb second-half equaliser before Konstandopoulos snatched all three points for the visitors in the first A-League match at Whitten Oval.

An 18-minute scoring blitz - driven by a dominant midfield performance - allowed Adelaide to take a 3-1 lead before the hosts pulled a second goal back shortly before half-time.

"We were very flat in that first half, probably the worst we've played in 45 minutes of football, in terms of the flatness and not doing the things that we worked on during the week. That's what I was most disappointed with," Western United coach Mark Rudan said.

The visitors opened the scoring in the ninth minute. Mileusnic ran down the left and slipped a pass to George Blackwood, who put the ball across the face of goal. United goalkeeper Filip Kurto could only parry to Mileusnic, who powered home.

The home side responded just three minutes later.

Max Burgess made light work of Ben Halloran, continued his run and slipped the ball to Berisha, who danced between the Adelaide centre-backs and scored.

It was to be a brief respite for the Victorians, as Adelaide regained the lead in the 15th minute.

James Troisi saw off Jerry Skotadis and delivered a terrific ball to release Blackwood, who again provided a telling pass across the face of goal for Mileusnic to toe-poke home.

The Reds made it three goals inside 18 minutes when Halloran's clever cutback found McGree, who took a touch then powered home a left-footed shot.

Western United managed to land a blow of their own with a timely riposte in the 43rd minute.

Skotadis released Connor Pain, with the wing-back playing a 1-2 with Burgess before delivering a ball to the near post for Berisha to convert.

The breathless attacking play continued after the break, with the home side finding an equaliser in the 54th minute when the mercurial Diamanti danced around a defender and curled a left-footed strike beyond the reach of Paul Izzo.

It took the introduction of substitute Konstandopoulos to tip the balance. Just seven minutes after entering the fray, the 23-year-old midfielder delivered a moment of magic to take home all three points for the visitors.

McGree's ball into the area saw a shallow clearance directed straight into the path of Konstandopoulos, who opened up and unleashed a vicious strike past a diving Kurto and into the back of the net in the 79th minute.

"We are glad we won this game and I think in the end, when you counted the chances, we deserved to win," Reds coach Gertjan Verbeek said.

"But it also could have been a draw, if you see how the game was going."

The win sees Adelaide leapfrog United to take fifth place on the table.

Australian Associated Press