Audi‘s René Rast ended the DTM Series practice at the Hockenheimring as fastest.
The inform driver has claimed the last four victories in the series and will be hoping to maintain this form in the final two races and retain his crown.
Stable-mate Jamie Green was second fastest, with Mercedes‘ Dani Juncadella third.
Championship leader Paul di Resta was down in thirteenth with second placed man Gary Paffett in fifteenth.
In the opening minutes of the session, the focus was largely on getting to grips with the circuit and making any adjustments accordingly in the pits.
Championship challenger, and reigning champion Rast set about using the opening moments of the session to pump in fastest laps.
The German set a strong benchmark time and held an advantage of over half a second over BMW‘s Bruno Spengler in second.
On his first timed run, second placed man in the championship Paffett could only manage eleventh fastest, over seven tenths behind Rast’s leading pace.
Championship leader Resta could not do any better on his opening run and found himself in sixteenth.
With his second timed run, di Resta leapfrogged Paffett to put himself into thirteenth but still a way off Rast ahead.
With just under ten minutes remaining on in the session, the majority of the drivers were circulating out on track however no one was putting in a time that looked likely to beat Rast’s time.
Mercedes‘ Edoardo Mortara meanwhile was in the pits having only completed three laps and having not put a lap time on the board, which the team confirmed was due to an electrical problem.
In the final moments a test of the slow zones was put into place, with the drivers then heading round to the grid to complete practice starts.
With drivers not making an improvements at the end of the session, it was Rast who remained on top.
Jamie Green was second with Dani Juncadella third.
The 2015 DTM champion Pascal Wehrlein was fourth, with Loïc Duval in fifth.
BMW quartet Timo Glock, Joel Eriksson, Philipp Eng and Augusto Farfus were sixth, seventh, eighth and ninth.
The top ten was completed by Nico Müller.
Championship leader di Resta could only manage thirteenth, with Paffett in fifteenth.
Second practice gets underway at 9.00 CEST tomorrow.
2018 DTM Series Results: Hockenheim II – Free Practice One
|13||3||Paul di Resta||GBR||Mercedes||+0.586|
|18||48||Edoardo Mortara||ITA||Mercedes||No Time|