Valtteri Bottas was fifth fastest in the second Mercedes, ahead of Renault's Carlos Sainz, Haas' Romain Grosjean, McLaren's Fernando Alonso and Vettel down in ninth place after completing just 12 laps.
"Luckily the team had me on a great strategy and therefore managed to get me back into second place with a brilliant pit stop". We were half a second behind these guys and I was thinking there's no way I'm going to be able to find half a second.
"We didn't come here expecting to lose 10 points", a seething Vettel told reporters after finishing behind Hamilton and the Red Bull of Max Verstappen.
Ricciardo has failed to finish the last two grands prix since Formula One returned from its summer break but the Australian again showed his street circuit prowess by clocking one minute, 39.711 seconds in the scorching Singapore sun. "That includes Lewis' lap as an individual, but (also) them as a team".
"Mercedes obviously got everything together yesterday - credit to them", said Vettel.
Winning from pole on one of the hardest tracks for overtaking in F1 was nothing special in itself. "I know that not a single member of the hierarchy, like [strategist] James Vowles or Toto probably, really didn't think that was possible - maybe more of them".
"I had a few driveability issues again behind the Safety Car and pulling away from the pit stop was awful, but in the end we managed it well and got the result we wanted".
It afforded him a more relaxing race than expected - heat aside - given Ferrari's advantage during practice this weekend. "What we tried to do was get to first position and get ahead, but Lewis was too quick". I can't remember one that I though I could do more.More news: NAFTA: "store supply management, " said Teamsters Canada
"With the way we raced today we didn't have a chance".
The German has often made good starts this season and his British Grand Prix victory in July was set up by passing Hamilton on the run to the first corner.
"We had a very strong package, both Kimi and myself looked very competitive throughout practice", noted Vettel.
"I'm spent, " Hamilton said moments after victory, crouching down by his auto.
Hamilton's stunning pole Saturday was a record-extending 79th.
Vettel pitted on lap 15 in his bid to undercut Hamilton for a new set of ultrasofts but Hamilton managed to come out ahead of the German, albeit on a much slower soft tyre, hoping it would last for a successful one-stop strategy.
Once he had fended off Verstappen's attack, Hamilton cruised to victory, the Dutchman held at arm's length, and Vettel cruising similarly behind.
There's "no chance" of winning, Vettel moaned over team radio. "If [being aggressive] works it's great - today it didn't work by quite a bit".