"That's the magic of this award, it reminds me that I never set out to be an actor and I fell in love with the process," he says.
The role of an ageing man swinging between gentlemanly charm and fearful hatred of his family was originally written by playwright Florian Zeller for an 88-year-old actor, and Lim says such meaty roles are rare.
"I'd love to try it in 25 years, if I'm still around," he says.
Production of the Year goes to Leda And The Rage, written, directed and performed by Edith Podesta and staged during the annual The Studios season of the Esplanade - Theatres on the Bay.
The play about a survivor of sexual assault dealing with post-traumatic stress disorder also nabbed actor Jeremiah Choy the Best Supporting Actor for playing a psychologist and therapist.
Leda And The Rage was 57-year-old Choy's return to acting after 18 years - his last role was in 2000 for The Spirits Play presented by TheatreWorks. He has been focusing on directing theatre instead.
"It was an important comeback project for me. I've always wanted to work with Edith," he says, adding that it was both "scary and fun" to put his director's hat aside and return to acting.
Director Podesta, 39, says: "I'm so happy for Jeremiah and very happy for all the collaborators because their work is recognised. I'm also shocked and thankful - all the feels."
She last won the Production of the Year award in 2017 for the M1 Singapore Fringe Festival work B*tch: The Origin Of The Female Species.
The award for Best Director goes to Nelson Chia, 47, co-founder of Nine Years Theatre, for Pissed Julie, a co-production with his Nine Years Theatre group and the Macau Arts Festival.
He has won this award three times before and says the recognition has helped him.
"The theatre awards are very useful when we are interacting with international counterparts. International counterparts can't understand our work in just one meeting or browsing through our website. An award gives us some kind of credibility."
He also won Best Director last year for Art Studio, co-produced by Nine Years Theatre and Singapore International Festival of Arts 2017.
Both Art Studio and Pissed Julie featured Chia's NYT Ensemble, a group of actors who work together on a long-term basis.
The director says: "I think there's something quite special with working with actors again and again. At the same time that I push them and challenge them to excel, they are challenging me. How do I not see them in the same way as I saw them in the last production?"