On 4 June 2018, Mandžukić was named to Croatia's final 23-man squad for the 2018 FIFA World Cup. In the opening game against Nigeria, he caused Oghenekaro Etebo's own goal and won a penalty, that was successfully converted by Luka Modrić, as the game ended as a 2–0 win for Croatia. During the side's round-of-16 match against Denmark on 1 July, he scored the equalising goal in the 4th minute of play; following a 1–1 draw after extra-time, Croatia prevailed 3–2 in the resulting penalty shoot-out. In the quarter-finals against hosts Russia on 7 July, Mandžukić provided an assist in the first half of regulation time for Andrej Kramarić's equaliser. A 1–1 draw after 90 minutes saw the match go into extra-time, and following a 2–2 draw after 120 minutes of play, Croatia once again progressed to the next round in the ensuing shoot-out, winning 4–3 on penalties. During Croatia's semi-final match against England on 11 July, with the score tied at 1–1 after regulation time, Mandžukić scored the match-winning goal in 109th minute to give Croatia a 2–1 victory, sending the team to the World Cup final for the first time in their history. In the final against France on 15 July, he became the first player ever to score an own goal in a World Cup final, when he headed Antoine Griezmann's free-kick into his own net to give France a 1–0 lead; he later scored Croatia's second goal by chasing down and capitalizing on an error from French goalkeeper Hugo Lloris, as the match eventually ended in a 4–2 defeat. With that goal, Mario Mandžukić became the second player in World Cup history to score for both teams in a single match (the first being Ernie Brandts of the Netherlands in a 1978 World Cup match against Italy) and the first to do so in a final.