Dominant Russell wins Australian Grand Prix in Mercedes 1-2
The pole-sitting Briton took the chequered flag by 2.974secs in Melbourne with Leclerc third and Lewis Hamilton fourth in a race that tested Formula One's new-look cars for the first time in competitive conditions.
World champion Lando Norris came fifth -- 51 seconds adrift -- in his McLaren with Red Bull's Max Verstappen a sensational sixth after starting from 20th following a crash in qualifying.
But there was disaster for home hero Oscar Piastri, who crashed on his out-lap to the grid and failed to start with major damage to his McLaren.
With the virtual safety car repeatedly brought out, pre-season favourite Russell stayed calm to clock a sixth Grand Prix win and his first since Singapore last year.
"Feeling incredible. It was a hell of a fight in the beginning," said Russell. "We knew it was going to be challenging.
"I made a bad start and some really tight battles with Charles at the start. Just really glad to cross the finish line."
Under new rules, half of every power unit now is a battery and drivers had to recharge while braking or by lifting off the throttle to avoid it draining.
The challenge of Melbourne's 58-lap Albert Park circuit was its long sweeping straights, which deplete batteries, and relatively few twisty turns to brake and charge it up again.
Five cars failed to finish as they grappled with the changes, including Piastri, Audi's Nico Hulkenberg, Red Bull's Isack Hadjar, Cadillac's Valtteri Bottas and Aston Martin's Fernando Alonso.
Strong pace
"Was not the best start we could have wished for, lost a lot of places and I had to recover," said Italy's Antonelli, who crashed heavily on Saturday and only just made qualifying after a major car rebuild.
"But overall was a good race, the pace was really strong especially at the end."
In fine conditions, Haas' Ollie Bearman was seventh and rookie Arvid Lindblad eighth in his Racing Bull. Audi's Gabriel Bortoleto and Alpine's Pierre Gasly rounded out the top 10.
"It was a very, very tricky race. None of us knew what to expect," said Leclerc.
"It has been quite challenging. It looked like Mercedes had a bit more pace than us today."
When the lights turned green Leclerc, on medium tyres, got a jump on Russell while Antonelli, who started second, slid down to seventh.
Hamilton also had a flying start for Ferrari and surged to third, ahead of Hadjar.
Russell immediately hit back, reclaiming the lead on lap two before Leclerc responded a lap later to go first again as they and Hamilton began pulling clear.
It morphed into a thrilling wheel-to-wheel battle at the front, with the lead changing hands three times on lap eight as Russell and Leclerc fought for supremacy.
The virtual safety car came out on lap 12 when Hadjar's car stopped with Russell and Antonelli pitting and coming back on hards.
Leclerc and Hamilton stayed out and when they resumed the Ferraris were 10 seconds clear of Russell, with Lindblad, Antonelli and Verstappen making up the top six.
The virtual safety car was again deployed when Bottas retired with Russell eight seconds behind the Scuderia when they got going again.
With his tyres starting to wear, Leclerc pitted on lap 26 but Hamilton stayed out and was passed by Russell before coming in.
Russell radioed that he thought a one-stop race was viable and he began pulling clear, with Antonelli second.
And there was no way back for the Ferraris, who were 15 seconds behind and barely made a dent in the Mercedes advantage in the second half of the race.
The season moves to China next weekend before Japan. Rounds four and five are scheduled for Bahrain and Saudi Arabia but are under threat given the war in Iran.