Goncalo Ramos headed in a stoppage header to keep alive Portugal and Cristiano Ronaldo’s hopes of winning the World Cup and break Croatia’s hearts in another knockout game packed with late drama.The 41-year-old Ronaldo, a five-times Ballon d’Or winner and one of the game’s greatest players, was substituted on 80 minutes having scored his first knockout goal from his country. It was a big decision by Portugal coach Roberto Martinez but paid off when Ramos headed in Rafael Leao’s cross.Portugal had the best chances of the first half with Bruno Fernandes seeing two shots blocked in quick succession and Ronaldo jumping past a header from Pedro Neto’s cross.The game erupted in the second half and it was Croatia who started stronger with Mateo Kovacic hitting the side netting before Ivan Perisic was allowed to take three touches to control the ball in the box and fire past Dominik Livakovic on 53 minutes.Ronaldo thought he had scored his first World Cup knockout goal when he controlled a high ball and brilliantly flicked it over Livakovik only to be ruled offside but his big moment came soon after. Martinez made a quadruple change on the hour mark, leaving Ronaldo on, and from a corner Renato Veiga was judged to have brought down Nikola Vlasic off the ball after VAR intervention.Ronaldo, playing in his ninth World Cup knockout game, scored from the spot on the 68th minute. A flurry of chances followed for both sides but seemingly to Ronaldo’s surprise he was substituted on 80 minutes, shaking hands with Martinez and his team-mates before sitting on the side of the dugout.The last 32 had already seen two games settled on penalties and two by stoppage-time goals and that became three when Ramos headed in and was embraced by Ronaldo.In a truly incredible finish, Josko Gvardiol thought he had equalised in the 103rd minute only for a VAR review using a snick-o-meter to show the ball had brushed Igor Matanovic on the way through, making Gvardiol offside.Portugal will now face Spain in Dallas on July 6.Here The Athletic’s Jack Lang, Thom Harris and Matt Slater break down the game’s key talking points.How did Ramos win it?Goncalo Ramos is a strange player. He is clearly talented but also diffident, a bullfighter who seems to have little taste for blood. His previous big World Cup moment for Portugal — that superb hat-trick against Switzerland in Qatar — seemed set to propel his career to the next level. Instead, he’s spent much of the time since sat on Paris Saint-Germain’s bench.For Portugal, it has been the same. He has never managed to make an unignorable case for himself, even as Ronaldo has declined. There was no real question of him being a starter under Roberto Martinez when this tournament began.Will his goal here change that? It remains to be seen. What we can say is that Ramos grabbed his opportunity with both hands. He only had one sight of goal — not a clear one, either — and he made no mistake, planting his header into the corner of Livakovic’s net. If Portugal are to go all the way this summer, he has already written his name into the story.Jack LangWhy did Croatia’s equaliser not count?Croatia thought they had an equaliser, deep into additional time, when Josko Gvardiol bundled a finish home from close range. The goal was initially allowed to stand, but replays showed that Mario Pasalic, who passed to Gvardiol, was offside.