[11] Following his impressive displays in the tournament, Antony returned to the first team, and with São Paulo struggling in the Campeonato Paulista, he began receiving more first-team minutes.

[15] Following the outbreak of the COVID-19 pandemic, the season was halted for various months, and as such Antony made his last appearance for the club on 14 March, featuring in the 2–1 victory over rivals Santos in the San-São derby.

[18] He made his debut in the UEFA Champions League on 27 October, in a 2–2 draw against Atalanta, leaving the field in the 90th minute, following a collision with Ruslan Malinovskyi,[19] before scoring his first goal in the competition on 3 November 2020, in a 2–1 away win over Midtjylland.

[21][22] The following season, despite the signings of Mohamed Daramy and Steven Berghuis, Antony kept his place in the starting line-up, and with his two goals and five assists against Sporting CP and Borussia Dortmund, Ajax became the first Dutch club to win all six Champions League group games in the competition's history.

Nine days later, while on international duty for Brazil national team, during a World Cup qualification match, Antony suffered an ankle injury, which ruled him out for the remainder of the season.

[26]"I was very happy in Amsterdam, I won titles at Ajax, made friends and built part of my career, but now I reinforce that I am ready and full of motivation to follow my story and my dreams.

After Ajax rejected the interest expressed by Manchester United for Antony's service, including an €85 million transfer bid, he failed to turn up to training, being left out of the matchdays squads against Sparta Rotterdam and Utrecht.

[28] In an interview, Antony revealed that he had wanted to leave in February, but he waited to the end of the summer window for the transfer to proceed, rejecting a contract renewal from Ajax in order to "follow his dreams".

[37][38] On 23 February 2023, Antony also scored the winner in a 2–1 Europa League playoff match, coming on as a substitute at half-time, over Barcelona, a day before his 23rd birthday.

[45] On 16 February, Antony scored his second La Liga goal for Betis, this time against Real Sociedad, while also providing an assist for teammate Marc Roca in the 3–0 rout.

[46] On 19 February 2025, it was announced that Antony had been nominated for La Liga Player of the Month after his successful season with the club, with his main rival for the award being Kylian Mbappé.

[56] On 4 September 2023, Antony was expelled from Brazil's squad for 2026 FIFA World Cup qualification matches against Bolivia and Peru following allegations of domestic violence against his ex-girlfriend.

[57][58] On 4 September 2023, Antony was removed from Brazil's squad for 2026 FIFA World Cup qualification matches against Bolivia and Peru following allegations of domestic violence against his ex-girlfriend, with Brazilian media outlet Universo Online reporting the existence of photos showing the ex-girlfriend having injuries to her head and her hand as the Greater Manchester Police begin to investigate the case.

[57] Amidst two other women also stepping up to accuse Antony of assault, he went on to firmly deny the allegations on Brazilian network SBT on 9 September, claiming that he will "provide the proof and people will understand".

[59] On 10 September, Manchester United issued a club statement acknowledging the allegations and announcing that an agreement with Antony was in place to grant him an extended leave of absence following the international break as he dealt with the situation.