Lewis Hamilton produced a bruising practice performance that put even Formula One title rival and team-mate Nico Rosberg in the shade.
Hamilton, claiming to be rejuvenated and reinvigorated following the sport's summer break, underlined such remarks by comfortably topping the Friday timesheet ahead of Sunday's Belgian Grand Prix.
Hamilton, 11 points adrift of Mercedes team-mate Rosberg with eight races remaining, conjured a time of one minute 49.189 seconds for the seven-kilometre Spa-Francorchamps circuit, finishing a staggering six tenths of a second clear of the German.
Rosberg had edged Hamilton in FP1 by a mere 0.097secs as Pirelli's medium-compound rubber - the slightly slower tyre this weekend - took centre stage.
But come the soft-tyre runs in FP2, Hamilton crushed Rosberg, who ran wide on one of his final hot-lap attempts, scattering gravel over the renowned track.
Ferrari's Fernando Alonso was third quickest in both sessions, at least suggesting a podium is on the cards on Sunday even if both Mercedes run reliably, which has not been the case of late.
Alonso was three quarters of a second down on Hamilton, and the only other driver to finish within a second of the 29-year-old Briton.
Williams, considerably off the pace in FP1 but suggesting they had far more in the tank as they are expected to be Mercedes' closest rivals this weekend, showed a little more of their hand in FP2.
Felipe Massa was fourth fastest, but 1.138secs in arrears, with team-mate Valtteri Bottas a further two places and 0.340secs adrift.
Sandwiched in between the Williams pair, and suggesting McLaren are edging ever slowly towards respectability, was Jenson Button, albeit with the 34-year-old nearly 1.5secs down.
Toro Rosso's Daniil Kvyat and the only driver other than Rosberg or Hamilton to win a race this season in Red Bull's Daniel Ricciardo were seventh and eighth, the latter 1.8secs back.
As for Ricciardo's four-time champion team-mate Sebastian Vettel, the German suffered more technical misery this season as he sat out the entire second session due to his car requiring a power-unit change, so finishing at the bottom of the standings without a time to his name.
McLaren's Kevin Magnussen and Nico Hulkenberg in his Force India completed the top 10, both just under two seconds off the pace.
Ferrari's Kimi Raikkonen was a lowly 15th, albeit seeming to focus on long-run pace than outright speed as he finished 2.3secs behind team-mate Alonso.
Marussia's Max Chilton, on Thursday out of a drive due to what the team claimed were "contractual issues" but reinstated following a "change of circumstances", was 18th.
Chilton had sat out FP1 in favour of reserve Alexander Rossi, who appeared poised to become the first American for seven years to race in a GP.
Back behind the wheel of his car again, the 23-year-old Briton was five seconds behind Hamilton and 1.3secs off team-mate Jules Bianchi.
The Caterham duo of Marcus Ericsson and Andre Lotterer were 19th and 20th, split by just 0.043secs.
Three-times Le Mans 24 Hours winner Lotterer, making his debut at the age of 32 and 12 years after his only previous F1 experience with Jaguar as a reserve, has replaced Kamui Kobayashi, apparently for this race only.
Like Vettel, Lotus' Pastor Maldonado also failed to set a time after an inexplicable crash on his third out lap.
The Venezuelan appeared to lose his bearings as he put a wheel on the grass on a straight part of the circuit, pitching him into a spin and bouncing off one barrier across the track into another, forcing a red flag as his battered car was retrieved.