The talented Portuguese recalled moments of self-doubt where he felt as if he was simply making up the numbers, racing in a series in which others thought he may not belong, and fighting with his team-mate at the back of the field with his career in motorsport on the line.
"The bad times immediately come to the forefront of my mind because I came so close to giving up on many occasions in my career. It’s thanks to everyone around me that I never did," said an emotionally charged da Costa post-race in Berlin on Sunday.
Da Costa joined Formula E in its inaugural season in 2014/2015, but by season three, now racing alongside Robin Frijns at Andretti, the competitive nature of the championship was taking its toll.
“We were killing it to beat each other for 19th, 20th position, being lapped by Lucas (di Grassi), Jean-Eric (Vergne), and Sebastien (Buemi) - the same guys I've shared the podium and raced with here in Berlin,” said the 28-year-old.
"Drivers kept looking at me and Robin like we were out of place, with little respect at all. In those seasons, three and four, there was little he or I could do but fight amongst ourselves.
“Season one was like ground zero. We never really had a chance but I showed a few things," he continued, undoubtedly referencing an unlikely maiden win in Formula E back in Buenos Aires in 2015. He led just one lap in the then Amlin Aguri throughout, but the most important one, as he took the chequered flag first. "Season two, was tough and in seasons three and four, there was nothing I could do.”
A promising junior career saw da Costa rise through the ranks from karts at the age of nine and then into single seaters, before being selected for a Formula 1 test drive and as one of Red Bull’s Young Driver Programme members.
But Formula E became his home and his formative seasons produced eighth, 13th, 20th and 15th in the standings, though da Costa had shown enough to catch the eye of BMW with the German giant joining Formula E full-time in 2018/19, and retaining him for a prized manufacturer drive.
In the midst of his moment, and the adulation after clinching the title in Berlin, he insisted on passing on his deepest gratitude to former team-mates whose trust and belief had helped him drive forwards – and prevented him from walking away.
“Red Bull were the people that really projected me,” said da Costa after the podium celebrations. “I was about to give up on my career but within four months of giving me an opportunity, they had given me the chance to drive four title-winning cars.
“After them, the people I really need to thank at this stage are the BMW family. Life is sometimes like this, and we went our separate ways, but those guys turned me into a real professional racing driver and I am really grateful for it.”
Da Costa joined DS Techeetah last year during the off-season, making the difficult decision to leave BMW i Andretti Motorsport – the team that, in its Andretti guise, had placed its faith in him after he left Red Bull’s junior programme.
At Techeetah he linked up with team principal Mark Preston once again, having raced for the team managed by the Australian back when it competed under the Aguri banner in the series' first two seasons.
Da Costa headed into Formula E’s mid-season break, enforced by the coronavirus pandemic, at the top of the standings.
However, at Tempelhof, he has been untouchable amid unprecedented circumstances, winning the first two races in the first of three double-headers, whilst becoming only the second driver in Formula E after Sebastien Buemi to win three in a row.
He built a commanding points advantage heading into the final four rounds to clinch the title in Round 9, with second place behind team-mate Jean-Eric Vergne.
“I started working with Antonio in season one and he’s been looking for a win like this ever since,” said Preston. “To do it in such dominant style is just fantastic for him – it’s all his dreams come true in just one year.”
Da Costa, who is known as one of the most popular figures in the Formula E paddock, credited his team for its work ethic - something which took him aback when he arrived mid-way through last year - as well as its unwavering support as he settled in for season six.
"I came to DS Techeetah because I wanted a faster car, as I want to put myself in a position to win races in my career and this is what we have managed to achieve,” added the Portuguese, a keen surfer.
“I have to take my hat off to the team. The hard work they have put in has been unbelievable. They will do whatever it takes at all hours to win and I am so grateful for it.”
"I thought I was a hard worker until I joined DS Techeetah. In my first week I saw how they operated, and the dedication they have and told them I’m not surprised how they win so much. That moment was when I understood I’d get the chance to do it myself.
“I have raced with these guys since season one. They knew what I could do even back then, when I was finishing nowhere, and they brought me back into the fold.
“Having the right stuff beneath me, the right car, and being part of the right team; it’s shown what I can do."
What’s even more remarkable is that he has outshone double title-winner Vergne in Berlin.
Da Costa was quick to pay tribute to the squad’s reigning champion, who pushed him hard whilst imparting the knowledge necessary to become a successful component of a championship-winning team operating at the forefront of the most competitive motorsport series on the planet.
"JEV (Vergne) is an amazing champion and he is a hard bone to chew," said da Costa, employing a delightful colloquialism. "He gave me a tough time this season on-track but always raced fairly and he’s a big part of this for me - I owe him a massive thanks.
"He has helped me out a lot and it’s also thanks to him that I was able to be so quick straight away in this team."
Two-time champion Vergne knows the ecstasy of success, and – like da Costa – is acutely aware of just how fleeting it can be.
“I know the feeling he has now, as you cross the line and you’re about to win your first title is the best moment in your life as a racing driver,” said the Frenchman.
“I’m so happy for him. In these extraordinary conditions, he’s done a fantastic job and he fully deserves to win the Drivers’ Championship. I tip my hat and of course, my congratulations also go to the team on winning the title. We couldn’t have dreamed for a better day. It’s an amazing achievement, and we proved that we were the best. I am very proud to be a part of it all.
“Antonio is very fast and it’s always important to have a team-mate that is faster than you at times. It keeps you motivated and working hard to better yourself. It’s been fantastic to have him here and I hope next year we don’t change a thing.”
The scale of his achievement is not lost on da Costa in either a personal or a professional sense. He left Tempelhof on Sunday evening as the foremost driver in a series in which all 23 of his rivals are at the top of their game - where each can win any given race in cars operated some of the most decorated manufacturers in motor racing history.
"In sport, and here we see it a lot in Formula E, we compete representing big brands and with a lot of people behind us and counting on us," said da Costa, who last won a title in 2009, competing in Formula Renault 2.0. "Sometimes people can be impatient and you’re only ever as good as you’re last result.
"I have had moments similar to this before, though never winning such a prestigious championship.
“In junior formulae, when you're climbing through the ranks, you compete against maybe five or six guys that might make it in the sport.
"Here, you’re up against 23 other guys who can win on the right day. You’re beating the best, and the paddock is full of talent across the teams, in the garages and on the grid. I have no words for what I'm feeling right now."