Adelaide United overcame Western Sydney Wanderers 3-1 in a pulsating grand final at the Adelaide Oval on Sunday to claim their first A-League title.

There was little to choose between the sides this season as they shared three draws but Adelaide, perhaps crucially, finished a point better off in the standings to secure the premiers' plate and home advantage.

Bruce Kamau put the hosts in front and Isaias' superb free-kick meant Guillermo Amor's men were firmly in control at the interval.

Western Sydney responded impressively and a spectacular strike from Scott Neville reduced the arrears but United substitute Pablo Sanchez had the final word.

After a subdued start, the final came to life with Kamau's second goal of the season in the 23rd minute.

The 21-year-old winger reacted quickly, stepping in front of flat-footed Wanderers defender Scott Jamieson to clip a shot beyond Andrew Redmayne.

Wanderers were almost level three minutes later when a sliding Mitch Nichols was unable to make contact with Brendon Santalab's dangerous ball across the six-yard box.

It was 2-0 to the premiers 10 minutes before the break as Isaias curled home a sumptuous effort to leave Redmayne with no chance and the Adelaide fans in ecstasy.

Tony Popovic's side refused to lie down in the second half and they were deservedly back in the contest when Neville struck magnificently before the hour.

A deft backheel from Santalab fell invitingly into the full-back's path and he crashed home an unstoppable angled strike from the edge of the box.

Industrious Adelaide striker Bruce Djite was unable to add to his 11-goal haul for the season as Redmayne blocked a near-post header.

There was a gripping end-to-end feel to the contest as it raced towards full-time, but Adelaide were carving out the better chances.

And Amor's men completed the remarkable transition from an eight-game winless run at the start of the campaign to become champions when Sanchez robbed fellow sub Kearyn Baccus and thumped gleefully into the far corner.