The #25 Audi R8 LMS was the class of the field in Sunday's contest, starting from pole and never looking to be under serious threat. Both drivers played an important role in the win, with Haase excelling during the first stint and Gachet completing the job in style during the second half-hour.
Having captured pole for the second run, Audi factory ace Haase delivered one of the most impressive performances of the season to build a gap of some 12 seconds by the time the pit window opened. The German driver was relentless at the wheel of his #25 R8 LMS, edging further away from the similar machine of Dries Vanthoor (#1 Belgian Audi Club Team WRT) with each passing lap.
It was telling that Vanthoor, one of the fastest drivers in the series, could not keep pace with Haase. This left the young Belgian to defend from the championship-leading #4 Black Falcon Mercedes-AMG driven by Maro Engel, which remained in his mirrors throughout the opening half-hour.
Haase's stellar stint put Gachet in a strong position once the driver change had been made, but the Frenchman still had work to do. In particular, he faced the prospect of Mirko Bortolotti chasing him down in the #63 Grasser Racing Lamborghini, which had vaulted to second place during the pit stops.
The Lamborghini had run fifth during the opening stint with Christian Engelhart at the wheel. The German stayed close to the pack, then let the Grasser mechanics do their work. A 41-second stop was enough to promote the car to second spot, beating the equally accomplished pit crews of WRT and Black Falcon.
But any chance of taking the win soon ebbed away as Gachet maintained an excellent pace throughout the second stint, matching Bortolotti all the way and maintaining a gap of around 10 seconds for the full 30 minutes.
Gachet was able to cross the line 9.9 seconds clear of the Grasser Lamborghini to seal his maiden Blancpain GT Series win and a first overall triumph for the French-based Sainteloc squad since it took victory at the 2017 Total 24 Hours of Spa.
Bortolotti took a comfortable second place, though the result will remain provisional as the #63 Lamborghini raced under protest. The car was disqualified from yesterday's second qualifying session after its data logger was found to not be working, a decision that the team has challenged.
The #1 Belgian Audi Club Team WRT entry completed the podium after Ezequiel Perez Companc fought off Luca Stolz in the #4 Mercedes-AMG throughout the second stint. This represented a perfect comeback result for the Argentine driver, who missed the previous round at Misano following his crash in the early stages of the Circuit Paul Ricard 1000kms. Now back to fitness, Perez Companc showed impressive composure to keep Stolz at bay.
The Black Falcon car continued to show metronomic consistency by taking its sixth successive top-four finish in Blancpain GT World Challenge Europe. Today's result edges the #4 crew further away at the head of the championship ahead of a seven-week break for the sprint-format series.
Charles Weerts completed the top-five in the #2 Belgian Audi Club Team WRT machine he shares with Christopher Mies, while yesterday's winning #88 AKKA ASP Mercedes-AMG was sixth after fending off the #563 Orange1 FFF Racing Lamborghini during the second stint.
A new title contender has emerged in the Silver Cup class, where the #62 R-Motorsport Aston Martin of Hugo de Sadeleer and Aaro Vainio completed a Zandvoort double by winning for the second race in succession.
The class was led for the first stint by the impressive Mattia Drudi (#56 Attempto Racing Audi), who was able to keep pace with the overall leaders. The Aston Martin then came to the fore during the second stint, with Vainio taking the lead from Milan Dontje in the #56 Audi and building a comfortable gap. While the #89 AKKA ASP Mercedes-AMG continues to lead the class championship, the R-Motorsport squad signalled its intent with two wins in the Netherlands.
Pro-Am honours went to the #333 Rinaldi Racing Ferrari as Rinat Salikhov and David Perel bagged a second class win of the campaign to reignite their title charge. The #333 crew suffered disappointment in Saturday's race when the car shed a wheel, costing them a potential victory, but there was to be no repeat on Sunday.
Jim Pla led the opening stint in his #87 AKKA ASP Mercedes-AMG and, like Silver Cup ace Drudi, impressed by running with the overall leaders. But the Rinaldi car remained in contention thanks to Perel, and Salikhov delivering an impeccable stint to finish 15th overall, well clear of the #52 AF Corse Ferrari. The lone Am Cup machine – the #444 HB Racing Ferrari – came home 23rd overall in the hands of Florian Scholze and Wolfgang Triller.
The Blancpain GT World Challenge Europe season has now passed its halfway mark, with two doubleheader rounds left to run at Nürburgring (30 August - 1 September) and Hungaroring (6-8 September). While the #4 Black Falcon duo of Engel and Stolz lead the way, several crews remain in contention for the series title heading into the deciding events.
Attention now moves away from sprint racing as the 2019 Total 24 Hours of Spa (25-28 July) takes centre stage. The season's marquee event is just two weeks away and will feature the majority of the teams and drivers that competed at Zandvoort. By securing victory in the Netherlands, Sainteloc Racing will take added momentum across the border to Belgium as it seeks its second Spa win in three years.
Christopher Haase, #25 Sainteloc Racing Audi: "To be honest, I was surprised to be so far ahead, but I had such good balance and speed in my Sainteloc Audi that I just had to keep up the rhythm. For me, today was really the perfect race. Thanks to all the team."
Christian Engelhart, #63 Grasser Racing Lamborghini: "At the start I nearly got a position, but I had to settle for P5 and stay there. It was a bit like a train. I think we had some more pace in the car but we couldn't take a risk to make a pass. I just stayed there and tried to be close when we came into the pits. The guys did an amazing job and this result is really down to them."
Dries Vanthoor, #1 Belgian Audi Club Team WRT Audi: "Mine was a tough stint. We kept it in front of the Mercedes-AMG, but it was really tough out there. I know Luca [Stolz] is fighting for the championship so he wouldn't take a big risk today. I kept it clean and made sure he stayed behind."
Aaro Vainio, #62 R-Motorsport Aston Martin: "My stint was really good. I had a Mercedes-AMG and a Lamborghini in front of me and I focussed on trying to catch them. I was closing up, so I am very happy about that. The team has done a really great job and we are getting closer and closer to the front. This was a perfect weekend and there's even more to come."
David Perel, #333 Rinaldi Racing Ferrari: "Yesterday was a disappointment, losing the wheel while running in the lead. Today we had a really good start, making up two or three places, and kept it clean from there. We waited for the over-cut in the pit stops and that worked perfectly, after which Rinat did an amazing job to bring it home. A huge thank you to Rinaldi for this weekend."