Ferrari ended a 45-race winless streak on Sunday to start Formula One's new era with a flourish and a one-two finish in Bahrain that sent the sport's oldest and most glamorous team back to the top.
"Mamma Mia!" exclaimed the Monaco driver after crossing the line to trigger wild celebrations and the sound of the Italian anthem.
While Leclerc became the first from the Mediterranean principality to lead the championship, Spanish team mate Carlos Sainz made sure the team secured maximum points from the evening.
"Ferrari is back and it's properly back, with a one-two and where the team should have been the last two years," said Sainz, who passed world champion Max Verstappen's stricken Red Bull before it retired.
"The hard work is paying off and we are there."
Ferrari have not won a title since 2008 and slumped to a 40-year low of sixth overall in 2020 before moving back up to third last season.
"A big, big congratulation to Ferrari," said Mercedes' seven times world champion Lewis Hamilton, who joined the pair on the podium.
"So happy to see them doing well again. They are such an historic, epic team. It's great to see Carlos and Charles up there as well."
A delighted Leclerc, who was also voted 'Driver of the Day' by fans, said the team could not have hoped for a better day.
"The last two years have been incredibly difficult for the team and we know this was going to be a big opportunity," he said after his third career win.
"Now it's starting in the best way possible... we couldn't hope for better. It's incredible to be back at the top."
Team boss Mattia Binotto said the one-two was a relief, and a big boost, but also an unexpected outcome on a day that ended in a nightmare for Red Bull with Sergio Perez also failing to see the chequered flag.
Verstappen had challenged Leclerc for the lead while Perez was heading for the podium before mechanical issues sidelined both.
Binotto -- in one of the hottest of hot seats in world sport -- said the closing stages of the race, with a safety car deployment 10 laps from the end, had almost given him a heart attack on the pit wall.