Rain clouds blanketed Watkins Glen Saturday morning, creating variable conditions for the 34 TUDOR United SportsCar Championship entries that lapped the 3.4-mile road course.

For the third time in three practice sessions since the event began on Friday, it was Michael Shank Racing’s No. 60 Ligier JS P2-Honda and driver Ozz Negri leading the field with a lap of 1:58.585.

The intensity of rainfall varied throughout the session, and at times, some sections of the track were less affected than others. Compared to Negri’s best of 1:38.055 yesterday, lap times were expectedly slow, and the Brazilian had the No. 5 Action Express Racing Corvette DP driven by countryman Christian Fittipaldi (1:58.907) and the No. 01 Chip Ganassi Racing Ford EcoBoost DP driven by Joey Hand (1:59.414) completed the top-3 in Prototype.

“I’m still learning the car; I’ve got it sussed out in the dry, but in the rain it’s a different animal,” said Negri’s teammate John Pew. “The car’s got a lot of torque and you’ve got to drive like there’s an egg between your foot and the accelerator.”

An early red flag stopped the session after only a handful of laps were completed when PR1/Mathiasen Motorsports’ Mike Guasch went off in the No. 52 PC, and once the session resumed with approximately 40 minutes remaining in the one-hour session, Porsche North America’s Patrick Pilet shot to the top of the charts in his GT Le Mans 911 RSR. The Frenchman, with Michelin’s advanced rain tires at his disposal, moved ahead of the Prototype field where all cars use harder spec tires from Continental.

A few of the Prototype runners eventually improved their times to overtake Pilet, and ran for about 30 minutes before another red flag halted activities when Michael Marsal slid off the track in his GT Daytona No. 97 Turner Motorsport BMW Z4. Cars returned to the track with six minutes remaining, but times atop the four classes went unchanged.

By the end of the session, Pilet’s best of 1:59.677 was still good enough for fourth overall and first in GTLM.

“The car is amazing in the rain; it was a lot of fun,” said Pilet. “The track is really special, we have a really good balance, and we’re hoping for rain (in qualifying). Michelin does an amazing job with tires.”

Pilet’s Porsche North America teammate Earl Bamber was second in GTLM in the sister 911 RSR (sixth overall, 2:00.745) and Bill Auberlen was third in his No. 25 BMW Team RLL Z4 (eighth overall, 2:00.879).

Conor Daly was fastest for Performance Tech in PC (2:01.297), a full 2.7 seconds ahead of Bruno Junqueira in the RSR PC (2:03.712) and 4.2 seconds clear of Rusty Mitchell in the JDC/Church PC in third (2:05.583).

Marc Goossens captured the best lap in GT Daytona (2:10.311) as his Riley Technologies Dodge Viper edged Kuno Wittmer’s TRG-AMR Aston Martin V12 Vantage (2:10.354) and Marsal’s aforementioned BMW which earned third with teammate Markus Palttala behind the wheel (2:11.724)

Up next for IMSA at Watkins Glen is qualifying which runs from 3:40-5:10 p.m. ET.