Hamilton and teammate Charles Leclerc were both called in on lap 39 by Ferrari under a virtual safety car caused by Lance Stroll breaking down.
Seven-time world champion Lewis Hamilton admitted he botched a call over tyres that cost him and Ferrari a second podium place at the Singapore Grand Prix on Sunday.
Hamilton and teammate Charles Leclerc were both called in on lap 39 by Ferrari under a virtual safety car caused by Lance Stroll breaking down.
Leclerc took advantage of a cheap second pit stop under the "VSC" to get rid of his medium tyres for a fresh set of softs and eventually finished second.
But Hamilton decided to stay out in second place on his much older soft tyres, a decision that would cost him dearly as he ended up having to go a marathon 44 laps on that compound to the end of the race.
First Hamilton was passed by Leclerc, then Kimi Antonelli, Lando Norris and Oscar Piastri to finish sixth -- almost 46 seconds behind Leclerc at the chequered flag.
"Sorry, boys," Britain's Hamilton said on team radio.
"I let you down today with that strategy. My call, and I lost us valuable points. I'll try and make up for it in the next one. Great job with the pit stop though."
Hamilton's engineer Carlo Santi replied: "Understood, thank you, Lewis."
But Ferrari team principal Fred Vasseur was not so conciliatory.
"We called him, we called them both to pit," he told Sky Sports.
"He missed the pit entry, and honestly it's a bit of a shame because he's losing a podium also.
"It was crystal clear on the radio.
"But now let's be focused on (the next race) Austin. The performance this weekend was OK. We have to be focused on the future."
Hamilton's blunder means his lead over fourth-placed Max Verstappen in the drivers' standings has been cut to eight points, following the Dutchman's maiden Singapore Grand Prix victory.