Lawson was first behind the wheel of the Red Bull RB21 on Wednesday and clocked up just over a full race distance.
His run was punctuated by a handful of moments and a spin as he exited Turn 2.
The New Zealander appeared to catch the apex kerb at the left-hander, which unsettled the car and brought the rear around.
As he countered the slide, the car gripped once more and pitched him into a half spin in the opposite direction, skidding to a halt without incident or damage beyond a set of flat-spotted tyres.
Lawson was one of two drivers to come unstuck over the course of the day, with Isack Hadjar at Racing Bulls having a moment at Turn 4 later in the day.
Conditions in Bahrain didn’t help, with cooler-than-expected ambient temperatures and blustery winds.
“The winds pretty tricky out there,” reasoned Red Bull team boss Christian Horner.
“I think it just caught him out on the exit of Turn 2.
“We’ve seen a lot of cars having different moments as the gusts are pretty strong out there.
“But I think Liam’s had a good first official session for us and settled in well so far.”
Horner’s view was shared by Lawson, who was unperturbed by his spin.
“I had so much fun out there today and it was so good to finally drive the new car properly and do some laps,” he said.
“It feels okay but obviously it is very early days, so it’s very much about learning at the moment.
“For me, there is a lot more to come because I need to learn a lot.
“From a team side we are just trying to learn about the new car and optimise these testing days,” he added.
“We had a plan of test items, and we managed to go through the whole plan, which is always good.”
Expected to be one of the leading contenders this season, Red Bull didn’t look as sharp on track as McLaren or Ferrari.
With Verstappen also having moments during his session it hinted at a nervous car for Red Bull, though that did settle down later in the day.
“We go into tomorrow with a lot more running and a better idea of where to improve the car,” Lawson explained.
“It’s hard to tell where we are in terms of pace but the car feels good to drive and comfortable.
“Testing is just as important to me, as it is for the team to learn about the car. It’s crucial to maximise these days before Melbourne.”
