Ferrari's Sebastian Vettel clocked in with the fastest lap in Friday's first free practice session, the local hero outpacing teammate Charles Leclerc by a quarter of a second while Mercedes Lewis Hamilton was third.
Both Scuderia chargers achieved their benchmark lap in FP1 on Pirelli's soft compound while Hamilton was 0.302s adrift on the medium tyre.
The soft-shod Red Bull of Max Verstappen was fourth, Valtteri Bottas was fifth, over 0.3s behind Hamilton, while Pierre Gasly rounded off the top six.
Hockenheim's weather forecast predicted on Friday morning that today's free practice sessions could turn out to be the only dry running of the entire race weekend.
Regardless of how the weather develops, high temperatures will remain the norm, which in turn put Mercedes in cautious mode in light of the W10's cooling issues.
The entire field - except for the two local crowd-pleasers which was the Mercedes duo - took to the track when the lights went green for routine installation laps.
McLaren's Carlos Sainz was the first driver to put his name at the top of the board, followed by Red Bull's Pierre Gasly, but the times were not particularly significant.
A red flag period erupted after 20 minutes when Kevin Magnussen's Haas stopped on track, with no power. The Dane was eventually towed back to the pits where the team identified a minor engine sensor issue.
Max Verstappen set the first benchmark time with a lap in 1m16.100s achieved on medium tyres, but the presence on track of both Mercedes kicked things into motion.
Bottas' opening effort on soft tyres put the Finn in command with a 1m14.805s that edged Hamilton by 0.048s while Ferrari's Leclerc was third, followed by Verstappen.
Racing Point saw some early signs that its latest upgrades were improving the performance of its RP19 as both Sergio Perez and Lance Stroll positioned themselves among the top-ten during the first sixty minutes of FP1.
Pushing a bit, Hamilton overhauled Bottas at the top of the timesheet but both Mercedes drivers were on the ragged edge on the exit of the last corner.
Meanwhile, Sainz shot to third followed by Haas' Romain Grosjean, with both men running on Pirelli's soft compound.
Also running on softs, Leclerc popped up at the front with a 1m14.268 that beat the medium-shod Hamilton. Verstappen also improved to slot himself into third in front of Bottas.
Behind the top four, Gasly also made good use of a set of softs to clock in fifth, albeit five tenths behind his Red Bull teammate.
Running a bit under the radar until 20 minutes from the end of FP1, a soft-shod Vettel put himself in gear to dispatch Leclerc at the top by 0.255s.
No improvements from the usual suspects in the closing stages of the session allowed Vettel to close out the morning in the lead.
However, with minutes to go, Bottas suffered a mishap at the Sachskurve where the Mercedes brushed the barrier but managed to extract himself from the gravel trap and coast back to base.
Behind the Ferrari-Mercedes-Red Bull top six, Sainz was once again 'best of the rest' in P7, the Spaniard heading Grosjean, Stroll and Renault's Daniel Ricciardo.
Down at the lower end of the proceedings, Robert Kubica validated Williams' upgrade package, outpacing teammate George Russell in FP1, although the Pole was still a hefty 2.5s off the pace.