in gtlm, magnussen's no. 3 corvette drafted his teammate gavin and took his fourth class pole position in the series. he suppressed hand's 2017 category lap record of the track with a time of 1 minute and 42.779 seconds. magnussen was 0.019 seconds faster than hand's no. 66 ford in second place. following in third was vanthoor's no. 912 porsche, with the sister no. 911 car of pilet in fourth. westbrook completed the top five class competitors in the slower ford. daniel serra in the no. 51 spirit of race ferrari 488 gt3 was the first driver to record a gtd lap time in the 1 minute and 46 second range midway through. this secured him the second pole position of his career, and his first in any class since the 2016 monterey grand prix with a 1-minute and 46.407 seconds lap. molina made it an all-ferrari category front row in the no. 82 risi car. the no. 11 grt lamborghini of mirko bortolotti was the third-fastest class qualifier. the car was demoted to the rear of the gtd field for failing a mandatory stall test in a post-qualifying technical inspection. hence, jack hawksworth in the no. 15 3gt racing lexus rc f gt3 inherited third. alessandro balzan's no. 63 scuderia ferrari started fourth, and dominik baumann's slower lexus fifth. two gtd cars failed to record a lap time: the no. 73 park place porsche tire punctured on its out lap, and p1's no. 73 mercedes-amg gt3 had brake problems.