Preining had looked set for a third career victory in the DTM having led the race comfortably from pole position until the final 10 minutes, when his Manthey EMA team was found to have not correctly completed the pitstop procedure.
The 24-year-old was handed a long-lap penalty for the infringement, leaving him down in third and elevating Toksport WRT duo Engelhart and Tim Heinemann up to first and second positions.
At the start of the race, Preining pulled away cleanly from pole, while Grasser Lamborghini’s Clemens Schmid slipped past Heinemann to split the two Porsches.
Dennis Olsen got the jump on the SSR Performance Lamborghini of Mirko Bortolotti to take fourth, while eventual race winner Engelhart was only sixth at the end of the opening lap after passing the Bernhard Porsche of Ayhancan Guven.
By lap eight, three-time champion Rene Rast had broken inside the top 10 but the right-rear tyre of his Schubert BMW suddenly came off loose, sending him into the gravel trap and out of the race.
When the consequent safety car peeled into the pits and the action resumed, Preining was rapid in his reflexes and retained the lead of the race, while Heinemann managed to overtake Schmid to establish a Porsche 1-2 again.
The pitstop sequence followed soon after, with Preining again managing to stay in front after pitting 32 minutes into the race.
Source: Autosport