At the 2019 AFC Asian Cup, the video assistant referees were used in the tournament for the first time, as well as an expansion to 24 teams. In addition, a fourth substitution was allowed during extra time. The tournament, hosted by the United Arab Emirates for the second time, witnessed the rise of Qatar, who conquered its first ever Asian title after beating Japan in the final 3–1. The tournament was marred by the Qatar diplomatic crisis, due to the UAE's entry ban on Qatari supporters, as well as shoe-throwing in the two's semi-final clash.