Daniel Keilwitz and Marvin Kirchhoefer secured victory in Sunday’s second ADAC GT Masters race at the Red Bull Ring, as Callaway Competition completed a sweep of the weekend.
The Corvette C7 GT3 R pair worked through a period of wet weather bookended by two dry spells to win the 60-minute contest, after Keilwitz led away from pole position.
With rain falling shortly after the start, Callaway chose to wait until the opening of the driver swap window to perform its switch to wet tires, while other teams elected to run a two-stop strategy by coming in sooner.
Kirchhoefer assumed the lead with around 20 minutes to go when the off-kilter group pitted right at the end of the window, before going on to extend his lead over the chasing one-stop pack as the circuit started to dry.
The Corvette driver crossed the line 4.2 seconds ahead of Mirko Bortolotti, who hauled the ORANGE1 by GRT Grasser Lamborghini Huracan GT3 into the top two with a scintillating charge from 24th on the grid.
Bortolotti, who took over from Andrea Caldarelli, inherited slick tires during the Huracan’s only stop to give himself a substantial pace advantage when the rain cleared up.
The Italian first dispatched Mikkel Jensen’s Schnitzer-run BMW M6 GT3 at the penultimate corner, before dragging past Filip Salaquarda’s ISR Racing Audi R8 LMS GT3 on the next lap.
Bortolotti then caught and overtook Markus Pommer in the No. 47 HTP Motorsport Mercedes AMG GT3, which Maxmilian Goetz started, on the final tour.
Pommer, who was on wets, moved up to second with a measured overtake on the inside of Filip Salaquarda at the Remus right-hander with 10 minutes remaining, before Bortolotti came through.
Pommer held on to take third, with no threat from Jensen or Salaquarda who ended up fourth and fifth on the same tire strategy.
In sixth was Luca Stolz in the Zakspeed Mercedes started by Sebastian Asch, while Ezequiel Perez Companc came seventh in the No. 19 Grasser Racing Lamborghini Huracan GT3.
The result means Keilwitz and Kirchhoefer move to the top of the standings, having leapfrogged the Herberth Motorsport Porsche pair of Robert Renauer and Mathieu Jaminet, which finished 10th.
It also marked the first one-two for the Callaway Competition outfit in GT Masters since the 2014 visit to the Red Bull Ring, when Keilwitz co-drove with Oliver Gavin.
RESULTS: Race 2