Charles Leclerc started on pole for the third time in a row at the Singapore Grand Prix, but a strategy call from Ferrari meant Sebastian Vettel came out in front of his team-mate, but Scuderia managed a third win on the bounce following up victories in Belgium and Italy.
Mercedes are now without a win since Hamilton's dramatic triumph in Hungary before the summer break and the five-time world champion has called on the reigning champions and the constructors' championship leaders to "step it up" to match Ferrari's level.
"I knew that we should have undercut," Hamilton said to reporters after the race, with the British driver repeatedly saying "let's undercut" on the team radio during the race.
"I knew it this morning as well in the brief, I was like I should take the risk, but they didn't. But we win and lose together as a team so we will take this on our chin. It's painful for us because we could have easily won today but it just didn't work out.
"It feels like they are hungrier than us. We've just got to step it up."