The Portuguese cemented a famous victory at the inaugural Cape Town race after passing Jean-Eric Vergne around the outside of the flat-out Turn 8 on the penultimate lap, having done the same to Nick Cassidy to secure his earlier lead.
On both occasions, da Costa gathered great momentum out of Turn 7 and reeled in his fellow podium finishers in over the stretch along the beachfront.
He caught both Cassidy and Vergne off-guard to sweep around the outside and claim the inside line for the ninth corner.
Reflecting on his moves, da Costa says that he felt empowered to make those passes as he had "the right guys" next to him on-track, and trusted them not to make any dangerous ripostes.
"The two or three of them I think I pulled into T8 and T9, they were great, but I knew I had the right guys next to me, you know, to cooperate through these overtakes.
"And obviously I was up on energy, so I could afford to pull these overtakes. It feels really good.
"The race played out perfectly for us with the second safety car, making everyone having to save a little bit more energy. So that helped me.
"I tried to save a little bit of energy in the first 40% of the race, and the race came to us. So, you know, everything just played out how we wanted it to.
"Some days it's like this, it just comes your way. And I'm happy that I was able to pull the rabbit out of the hat when I had to."
Da Costa admitted that his defence against Vergne on the final lap could be viewed as "a bit over the limit", but enjoyed the battles that he had through the field from 11th on the grid.
After a difficult start to the year, da Costa said that his progression through his first year with Porsche meant that his success in Cape Town had a "special taste".
"The journey is the fun thing about, about what we do. Winning and all that is great, but we go through some tough moments as athletes and it hasn't been an easy first couple of months of the year for me.
"So this has a special taste, obviously racing amazing drivers and I can trust them to pull out these overtakes. Both of them were tough, but very fair.
"If anything, actually on the last time I was a bit over the limit defending from JEV. But it was a fun race with a lot of overtaking."
