The star batsman put a run of low scores behind him to make 76 as he was named player of the match, with the 35-year-old Kohli saying afterwards: "This was my last T20 World Cup, and this is what we wanted to achieve.
"One day you feel you can't get a run, then things happen. God is great, and I got the job done for the team on the day it mattered.
"Now or never (that was my) last T20 for India, wanted to make the most of it. Wanted to respect the situation rather than force it."
Kohli, pressed on whether he had played his last T20 international, added at the presentation ceremony: "This was an open secret, it's time for the next generation to take over, some amazing players will take the team forward and keep the flag waving high."
Former India captain Kohli, one of the outstanding batsmen of his generation, scored more on Saturday than he had in the rest of the tournament.
Prior to the showpiece match at the Kensington Oval, he had managed just 75 runs in seven innings during the competition.
'None of us doubted him'
India captain, Rohit Sharma, who opened the innings alongside Kohli, had been the team's form batsman leading into the final with 248 runs, including three fifties, at an average of over 41.
But it was a case of role reversal on Saturday, with Rohit out for nine as India slumped to 34-3.
Kohli, however, rebuilt the innings during a stand of 72 with Axar Patel (47) that helped take India to 176-7, before a superb bowling and fielding display restricted South Africa to 169-8.
"None of us doubted him, we know his quality," said Rohit of Kohli, who bowed out of T20 internationals with 4,188 runs in 117 innings, including one hundred and 38 fifties, at an average of nearly 49.
"He has been at the top of his game for 15 years now. Big players will step up in big occasions and he played a crucial knock today.
"It was a team effort to get to that total but we knew we needed someone to bat time and he did that perfectly, using all his experience," added Rohit.
Kohli's 59-ball innings included six fours and two sixes before he holed out off Marco Jansen.
Victory followed a 2023 where India had been beaten in both the World Test Championship final at The Oval in London and the 50-over World Cup final on home soil in Ahmedabad, with India losing each of those showpiece matches to Australia.
It also gave India their first outright global title since they won the 2011 50-over World Cup final against Sri Lanka in Mumbai.
After that match, Kohli carried Sachin Tendulkar on his shoulders during a lap of honour at the now retired India batting great's Wankhede Stadium home ground.
"Sachin Tendulkar has carried Indian cricket on his shoulders for 21 years," said Kohli at the time. "So, it was fitting that we carried him on our shoulders after this win."
Kohli, the only survivor from that 2011 triumph in the India team on Saturday, was modest when asked if the current side should give him similar treatment.
"Rohit has played nine T20 World Cups, this is my sixth," said Kohli. "He deserves it.
"I wasn't confident in the last few games, but grateful and humble right now, and I bow my head. It's been difficult, and the emotions of the game... it's difficult to hold things back. The emotions will come later."
