Melbourne Heart leapt into the A-League top six and left Adelaide United with a greasy grip on a top two spot with a 2-0 victory at AAMI Park on Friday night.
The Heart rebounded from their late capitulation to Sydney FC last weekend with a far more controlled performance against a Reds side which struggled for rhythm.
Goals in both halves to Josip Tadic and Richard Garcia secured the victory, pushing the Heart into fifth place.
Adelaide are in danger of both falling further behind league leaders Central Coast if the Mariners can pick up points against Newcastle Jets on Saturday and having third-placed Melbourne Victory close in if they succeed against Perth Glory on Saturday night.
As is their usual modus operandi, the Heart grabbed an early lead when striker Tadic headed home a Fred cross in the fifth minute with Adelaide's marking non-existent.
Both teams had dangerous patches of play and Adelaide could have equalised had Dario Vidosic done better on 42 minutes.
He shot well over the bar after Evan Kostopoulos had played him in on goal.
A minute later, Adelaide keeper Eugene Galekovic made a fine save to deny David Williams and Tadic was unable to make any meaningful contact with a difficult rebound.
But it took just four minutes after halftime for the Heart to go further ahead, when midfielder Matt Thompson dispossessed Kostopoulos in midfield, ran to the edge of the box, then played in Garcia who slotted home coolly.
While Heart are the best first half team in the A-League this season, they are also the worst second-half performers.
But they were rarely troubled by a flat Reds side in the second half - long-range shots from Kostopoulos and Cameron Watson late in the period their best attempts.
Both teams also have significant injury concerns out of the match.
Heart lost skipper Fred to what appeared a hamstring or quadriceps injury just 10 minutes into the second half.
And soon after Adelaide's Vidosic limped from the field to be substituted.