Scoring three minutes after coming on is a dream impact for any substitute, which is what the rangy Polvara did.
But it was not just the fact he scored but the quality of the goal itself which was so impressive. A cross was guided behind him by Adil Aouchiche, and he reacted brilliantly to get to the ball first.
His awareness and agility to swivel and hit it first time off his left foot was even better, with the ball kissing the inside of the post on its way in.
But Polvara did not stop there. Four minutes later, his pinpoint cross teed up Ester Sokler, whose header went narrowly wide.
At the death, Polvara’s sheer presence caused havoc in the box and, but for a good save, he might have won it for Aberdeen.
Overall, the American managed two shots, both on target, and created three chances, the joint most of any player.
According to Opta, he completed all 19 of his passes and won six of his eight duels, the joint most among Aberdeen players. He was everywhere.
“Polvara down that left-hand side was such an out ball,” Aberdeen legend Willie Miller said on BBC Scotland.
“He’s a big strong unit. And the goal – he shouldn’t be scoring from that position. Facing away from goal and he’s able to manoeuvre himself to strike it.
“That fired the crowd up and gave them the hope and optimism they could get something out of it.
“He made a huge difference. The aerial threat, the energy, the quality. He must be in the manager’s thoughts to start next week.”