Leapfrogging the Mariners and Melbourne Victory into third spot on the A-League ladder with the result, United dominated from the outset and at times were simply irresistible.
First-half goals to Marcelo Carrusca and Fabio Ferreira proved the difference, the Reds continuing to boss proceedings against a more resolute Mariners outfit after the interval with one of the slickest performances in recent memory.
"For me, this was the best game that we've played," Gombau said.
"We played the (desired) style and also we didn't make mistakes.
"In the past we made mistakes, last week (in beating Sydney FC) we made mistakes.
"We are confident ... you can have so much confidence, but in football you can lose.
"You can never relax.
"I want my players to know that to win is very difficult and they need to work all the week to play a good game."
The win looms as the perfect springboard for white-hot Adelaide, with just one loss from their past 10 starts, to travel to AAMI Park and tackle Victory next Saturday in the hope of avenging their disappointing 3-0 loss to their arch nemesis at Etihad Stadium in November.
That defeat still burns in Gombau's guts.
"For us it (next Saturday) is very important as it's a derby against Victory," he said.
"It's the game where afterwards I was most sad because we lost that game after missing a penalty.
"We need to win that."
Adelaide's eye-catching ball movement and exquisite passing will have been noticed by Melbourne, as was the Reds' inability to fully capitalise on their swag of second-half goal-scoring opportunities, perhaps the only token concern.
"We missed a lot of chances in the second half," Gombau said.
"It's something we need to improve. But in the end, the important thing in football is to create chances and we created.
"If you don't create these chances, you will be worried.
"We need to keep creating and improve in the scoring.
"At that moment, we'll be a better team."
