Following a wet, grey practice day on Friday, Hamilton emerged from his Mercedes bemoaning the car's lack of balance and claiming he could not recall the last time he was so uncomfortable.
Overnight, however, it appears the car has been transformed as the 28-year-old is firmly in the running to grab pole position during qualifying.
In final practice Hamilton topped the standings right up until the moment the clock counted down to zero, only for team-mate Nico Rosberg to knock him off top spot at the death.
Rosberg finished with a time of one minute 31.487secs, beating Hamilton by 0.146secs, with the Red Bull duo of Sebastian Vettel and Mark Webber just over half-a-second adrift of the German.
At this stage qualifying appears to be a shoot-out between Rosberg and Hamilton, with the Red Bulls also in the mix, but only just.
The best of the rest was Lotus' Romain Grosjean, albeit with the Frenchman just over nine tenths of a second off the pace.
Toro Rosso's Daniel Ricciardo looks on for a top-10 grid spot as the Australian was seventh on the timesheet, followed by Fernando Alonso in his Ferrari and Lotus' Kimi Raikkonen, but with the duo almost a second behind.
Force India pair Adrian Sutil and Paul Di Resta completed the top 10, a fraction over a second down, with McLaren's Jenson Button 12th and nearly 1.5secs adrift.
Not for the first time this season the session was overshadowed by another Pirelli tyre failure, with McLaren's Sergio Perez the one to suffer on this occasion.
The Italian manufacturer had hoped to introduce new rubber from this race as fears over safety had been expressed.
But wet weather throughout Friday practice in Montreal ahead of the Canadian Grand Prix resulted in a lack of running of the experimental tyre, forcing Pirelli to shelve plans at the time until this weekend.
Although further rain scuppered first practice yesterday, the tyres were finally given an airing in a drier FP2, but barely enough to satisfy Pirelli that they are the way forward.
In the meantime, Pirelli are understood to have strengthened the current specification of tyres with a new bonding glue, not that there was much evidence of that 15 minutes into FP3.
In the majority of cases this season a cut has caused the rubber to delaminate, but leaving the belt on the wheel.
In this instance, the left-rear tyre on Perez's McLaren 'popped' according to the Mexican, discarding the bulk of the rubber on the track.
By the time Perez had made his way back to the garage there was nothing left but the rim, sustaining considerable damage to the floor of the car in the process.
Given the debris strewn across the circuit, it resulted in a red flag and a six-minute delay.
Although Perez returned to the track, he suffered a slide and a run across the grass at Becketts, leaving him down in 18th and two seconds adrift.
Marussia's Max Chilton seemingly has work to do as he was 21st and 5.2secs down, but crucially 1.7secs behind team-mate Jules Bianchi.