The Mercedes driver was almost four-tenths clear of Max Verstappen at the end of the final practice hour to mark himself out as one to watch come qualifying.
Hamilton’s effort was backed up by George Russell who was third fastest, suggesting there’s pace in the Mercedes this weekend.
Between them was Max Verstappen, who was the first driver on track as Red Bull Racing looked to complete an early systems check in the Dutchman’s car.
Given Friday’s conditions were a mixed bag, the dry track saw all 20 drivers out early. However, their runs were interrupted when Zhou Guanyu spun at Turn 2.
The Sauber driver lost the back end as he rounded Turn 1 and gently backed into the barrier on the outside of Turn 2 where the car became beached on the grass verge.
Much of the first half of the session was dedicated to long run pace as teams looked to make up for lost time after Friday.
Some were looking at shorter runs, including RB, though none showed their hands until the qualifying runs began, about midway through the session, when a curious picture emerged.
With its new-for-Monaco front wing fitted to both cars, Mercedes showed impressive pace.
Hamilton in particular showed well, with his 1:12.549s leaving him well clear of the pack as he banked it.
Team-mate Russell was second best at the time, though couldn’t get within 0.7s of the seven-time champ.
Red Bull Racing left its run late, though Verstappen voiced concerns over his car’s handling back to the pit wall throughout the session.
The Dutchman had pace, but it wasn’t blistering, suggesting it will be another open qualifying session later in the day.
His best came inside the final minute of the hour but was 0.374s away from what Hamilton could muster.
Russell improved late on, reducing his deficit to 0.4s though was clearly not as comfortable in the car as his team-mate.
Also in the mix was Lance Stroll who ended the session fourth best for Aston Martin with a late lap.
Fernando Alonso in the Silverstone squad’s other car was eighth best, suggesting the green team could come into play for a top 10 berth in qualfying.
McLaren showed well, even if Oscar Piastri ended the session fifth and Lando Norris seventh.
On long run pace, Norris had demonstrated good pace through the middle third of the lap to paint McLaren out as a likely contender both come qualifying and then Sunday’s race.
Ferrari was less impressive with Charles Leclerc the best placed of the Scuderia’s two entries in 10th.
The Monegasque driver was 0.8s off the pace and seemingly without an answer when it came to closing the gap.
Carlos Sainz in the other car was no better, another 0.2s back in 12th.
But while Ferrari struggled, Daniel Ricciardo showed well to finish Free Practice 3 sixth for RB.
His best lap came later in the session after spending time earlier on working on single lap pace.
The difference between himself and Yuki Tsunoda in the other RB was notable, the Japanese driver 15th and 1.2s away from Hamilton’s best.
Qualifying therefore appears a battle between McLaren, Red Bull Racing, Mercedes, with Ferrari half a step back.
RB and Aston Martin also look contenders for Qualifying 3 appearances, though Logan Sargeant in 14th suggested Williams has something up its sleeve too.
Exactly how much is unclear as Alex Albon clouted the wall exiting the final chicane with 10 minutes remaining, damaging the suspension on his car and ending his session.
Qualifying for the Canadian Grand Prix begins at 16:00 local tie (06:00 AEST).