Hamilton was peerless at Spa-Francorchamps, leading every lap of the race from pole to beat teammate Valtteri Bottas by almost nine seconds.
The win was Hamilton’s 89th, just two shy of Michael Schumacher’s record 91 victories.
“I know it’s not necessarily what everyone always wants to see, to see the Mercedes out the front,” he said. “But no matter how much success we have, we just keep our heads down.
“Honestly, it’s crazy to think I’m 35 and going towards 36, but I feel better than ever, so that’s a positive.”
Hamilton now leads Max Verstappen and Bottas by 47 and 50 points respectively with 10 rounds still to race.
Teammate Bottas was ineffectual in second place. He was forced to defend against a fast-starting Max Verstappen on the crucial first run down the Kemmel Straight, which put him out of Hamilton’s range at the end of the first lap.
A safety car restart on lap 15 offered him a second chance to fight for the lead, but Hamilton perfectly judged his getaway to prevent friendly fire, and thereafter both cars had to manage their tyres to make the end of the race.
“I think Lewis was faultless today, and yesterday [in qualifying] he was quick,” Bottas said. “I’m just happy there’s an opportunity next weekend again.”
Verstappen finished a lonely third, his Red Bull Racing car in a league of its own behind the Mercedes cars but ahead of the midfield.
“It was pretty boring, to be honest,” he complained. “Not really interesting, not much to do.
“I couldn’t really keep up with them when they were pushing, and from my side I ran out of tyres in the end.
“It was not really enjoyable out there today.”
Daniel Ricciardo offered Verstappen a moment of excitement off the line, the ex-teammates battling for third through Les Combes after the Australian slipstreamed past the Dutchman down the Kemmel Straight.
Both had moments off the track on the run to Bruxelles but rejoined the road in qualifying order, with Ricciardo unable to make any further inroads.
But P4 was the Australian’s equal best result for Renault since joining the team last season, and he scored an extra point for fastest lap as he took the flag.
Teammate Esteban Ocon snatched fifth from Thai driver Alex Albon on the final lap. The Frenchman had pinched the place from the Red Bull Racing driver on the first lap but lost it with a slow pit stop, taking it back only as Albon’s tyres expired in the final laps.
Albon secured sixth ahead of Lando Norris, McLaren’s only entrant after Carlos Sainz’s car was withdrawn with an exhaust-related engine problem.
Pierre Gasly was a superb eighth, leaving his pit stop late to cut through the field on faster tyres and finish ahead of Racing Point’s Lance Stroll and Sergio Perez in the final points-paying places.
Ferrari endured its worst race in more than a decade, with both cars failing to score.
Sebastian Vettel and Charles Leclerc finished 13th and 14th and behind Kimi Raikkonen’s Alfa Romeo, an engine customer of the Italian team. Only three cars - two powered by Ferrari - finished behind the pair.
The Ferrari power unit was outgunned on Spa’s long straights, but the works team was also shown up as aerodynamically lacking in its lowest double finish without a crash since 2010.
Antonio Giovinazzi failed to finish after a crash at Fagnes, collecting and eliminating George Russell with it.