Hamilton and new team-mate George Russell were a distant fifth and sixth for the majority of Sunday’s race but a late Safety Car put them back in contention before Red Bull suffered a dramatic late double DNF.
Hamilton pounced after Sergio Perez’s spin to clinch a podium which appeared impossible earlier on, with the seven-time world champion more than half a minute off Charles Leclerc and Max Verstappen before the Safety Car.
“For sure I definitely didn’t expect it,” Hamilton admitted to Sky Sports F1. “I woke up this morning hoping, I had a super, super hope that we’d have a chance to fight, that we have a car that is better than we think.
“But we did struggle in the race. George did a great job and to get a third and fourth is pretty remarkable with the troubles that we have.”
Mercedes have dominated F1 and claimed every constructors’ title and all but one drivers’ crown over the past eight seasons, but are the third-fastest team to start 2022’s new era of cars and rules.
“You can see how you can manage expectations,” said team boss Toto Wolff. “If we would have come in third and fourth last year it would have been very frustrating. But this year I think we are punching above our weight class.
“I think third and fourth is a fantastic result.”
He added: “I think at the moment we are five and six, third on the road, and we’re trying to recover ground but it’s not going to come from one day to the other.”
Leclerc and Carlos Sainz clinched a Ferrari one-two in Bahrain, their first since 2019 with the Italian giants looking like genuine title contenders this season.