"Tony was in Wales, where he grew up, and he was asleep at 4 in the morning when I woke him up to tell him the news," Jeremy Barber, Hopkins' long-time agent, told PEOPLE. "He was so happy and so grateful."
Hopkins made history for his win for his performance in The Father; he is the oldest actor to win an Oscar in that category.
And while he was a few hours late to the celebrations, Hopkins took to social media the following morning to give a post-show acceptance speech while paying tribute to the late Chadwick Boseman — who was also nominated for the award.
"At 83 years of age, I did not expect to get this award. I really didn't," Hopkins admitted in the clip. "I'm very grateful to the Academy. Thank you. I want to pay tribute to Chadwick Boseman, who was taken from us far too early. And again, thank you all very much. I really did not expect this, so I feel very privileged and honored, thank you."
The 21 Bridges star tragically died in August at 43 years old after an undisclosed battle with colon cancer. Boseman recently won a Golden Globe, Screen Actors Guild Award and Critics Choice Award for his performance as Levee in Ma Rainey's Black Bottom.
Aside from Boseman, Hopkins also beat out Riz Ahmed (Sound of Metal), Gary Oldman (Mank) and Steven Yeun (Minari).
While fans gushed over Hopkins' performance and win, many felt Boseman was robbed of the title of Best Actor.
The 93rd Academy Awards — which was held in-person at the Union Station Los Angeles and the Dolby Theatre at the Hollywood & Highland Center — normally ends with the announcement of Best Picture; however, the academy moved Best Actor to the end of the ceremony.
The restructuring of the schedule indicated to many that Boseman was bound for the award. And since Hopkins wasn't present to accept his award, the ceremony came to an abrupt end.