Portugal captain Ronaldo became the first European player to make 50 appearances across the FIFA World Cup and European championships, but this Group F meeting belonged to Georgia.

Mikautadze teed up Khvicha Kvaratskhelia's second-minute opener in Gelsenkirchen before himself coolly converting a penalty after the break, sealing Georgia's first win at a major tournament.

Willy Sagnol's side will be rewarded with a Round of 16 meeting with Spain, while Portugal must improve for its clash with Slovenia in Frankfurt.

Roberto Martinez's men were stunned almost immediately when Mikautadze slipped Kvaratskhelia through to hammer into the bottom-right corner with a left-footed drive.

Timed at just one minute and 32 seconds, that was the quickest goal Portugal has conceded at a European championship, and Martinez's side was slow to respond.

Ronaldo tested Giorgi Mamardashvili's hands with a thunderous long-range free-kick, while Francisco Conceicao angled wide from a tight angle and Joao Felix fired an optimistic effort over.

Yet Georgia went close to doubling its lead as Kvaratskhelia's inviting free-kick narrowly evaded Giorgi Gvelesiani, before Joao Felix's fizzing effort was held by Mamardashvili at the other end.

Ronaldo was thwarted at point-blank range shortly after half-time as Lasha Dvali produced a heroic diving block to deflect over from a prone position inside Georgia's six-yard box.

Kvaratskhelia rushed a glorious chance near the penalty spot moments later and swiped at thin air, but Antonio Silva's clumsy hack on Luka Lochoshvili allowed Georgia to extend its advantage.

Referee Sandro Scharer pointed to the spot after VAR recommended an onfield review, and Mikautadze had no problem slotting past Diogo Costa's reach into the bottom-right corner after 57 minutes.

A frustrated Ronaldo was substituted with over 20 minutes to play before Nelson Semedo and Conceicao went close in the dying stages of an unexpected defeat, as Portugal limped into the knockout rounds.

Remarkably, Mikautadze now leads the UEFA Euro 2024 scoring charts after finding the net in each of his opening three games in Germany.

Mikautadze is the ninth player to score in all three group matches at a single championships, joining the likes of Michel Platini (1984), Ruud van Nistelrooy (2004) and Portugal's own Ronaldo (2021).

The omens for the rest of the tournament are positive, too, considering Georgia is just the second European side, after Greece in 2004, to claim its first win at the FIFA World Cup or European championships against Portugal.

Greece was a 2-1 victor in the opening match 20 years ago against hosts Portugal before taking home the title by defeating the Selecao again in the final.

Much has been made of Portugal's star-studded attack, with Martinez boasting the likes of the record-breaking Ronaldo, Bruno Fernandes and dazzling AC Milan winger Rafael Leao.

Yet there are defensive issues that need arresting before the knockout stage begins.

Portugal has conceded the opening goal in two of its three group-stage matches at the European championships for just the second time, with UEFA Euro 2012 the other instance.

This defeat also marked Portugal's joint-heaviest loss at a championships, alongside its 4-2 reverse against Germany at UEFA Euro 2020 and a 2-0 surprise upset against Switzerland in 2008.