Piastri ended Free Practice 2 with the eighth-best time, almost second down on Lewis Hamilton who stopped the session.
It was a gain from the opening hour, where the Australian had finished in the same position but 1.45s away from the pace.
Team-mate Lando Norris was second fastest in the second session, just 0.11s from Hamilton, highlighting the potential within the McLaren.
“It was tough,” Piastri said of the slippery conditions that greeted drivers
“I mean, very similar to last year I would say.
“Every lap we do, the track’s getting better and better.
“We knew what to expect this time at least.”
The Las Vegas Strip circuit is unique in that it is opened to traffic during the day.
As a temporary venue, it was also incredibly dusty when track action began.
Those factors resulted in significant track evolution, with times dropping by more than 10 seconds over the course day.
“I think the pace seems reasonable just a bit of tidying up,” Piastri reasoned.
“If you don’t get the lap here then you quickly lose a lot of time with the track evolving so much.
“When the red flag came out I was on a lap that was a fair bit better than the lap I did,” he added of his Free Practice 2 effort.
“But still some tidying up to do on top of that.
“The pace is there or thereabouts, just need to make sure I leave it out on the track.”
Based on the potential shown on Thursday’s practice running, Piastri and McLaren should feature somewhere towards the front of the field come qualifying.
However, it’s tight, with three teams arguably in the mix.
“Mercedes have looked very quick today; very, very quick,” the Australian observed.
“Ferrari have been pretty strong as well, but I think we’re definitely in the mix.
“Mercedes have had a pretty strong day but let’s see what happens tomorrow.”
A final hour of practice remains ahead of qualifying in Vegas, which begins at 22:00 local time on Friday (17:00 AEDT Saturday).
