Costa, 24, saved three penalties in the shoot-out, a record for a Euros finals, as Portugal advanced to a meeting with France on Friday. Before that he produced an excellent stop to deny Benjamin Sesko on a one-on-one in extra time.
He became the third keeper to receive a Man of the Match award at the tournament after Mamardashvili in a 1-1 draw with Czech Republic and Poland’s Lukasz Skorupski when they drew 1-1 against France.
“I think this was the game of my life,” Costa told reporters. “Maybe the game where I was most useful. I am very, very happy and I am also very excited that I helped the team.”
Mamardashvili, 23, stands head and shoulders above the rest of the keepers at the tournament in terms of shots saved, though he will not thank his defence for that.
He made 29 stops in the four games he played, including the 4-1 round of 16 loss to Spain, more than double the next highest for a keeper at the tournament.
Italy’s Gianluigi Donnarumma, Koen Casteels of Belgium and Jan Oblak from Slovenia all made 14 saves and are out of the tournament.
Georgia allowed 106 attempts on goal, so Mamardashvili deserves a great deal of credit for conceding only eight times.
His performances have not come out of the blue and the Valencia keeper has been attracting interest from top clubs for some time, coming close to a move to Bayern Munich at the start of last season.
“My move to Bayern Munich was almost done,” he told reporters. “My agent was in Munich with my father to find an apartment. But as far as I know, in the end they refused to pay 35 million (euros) for me.”
He has started all but one of Valencia’s LaLiga matches over the last two seasons and his exploits in the last few weeks may reignite interest elsewhere.
The keepers at Euro 2024 who played four games and had the fewest saves to make are Costa and Switzerland’s Yann Sommer with six each. Germany’s Manuel Neuer has made one more stop with seven.