British rider Scott Redding produced a brilliant late surge to top the opening Moto2 practice timesheets at Indianapolis.
The Marc VDS Racing rider posted a best time of 1.46.728 to edge out world championship leader Toni Elias by just 0.015s.
Redding came out on top in another closely contested Moto2 session with the top 32 riders split by less than two seconds.
Redding, who is looking to claim his first Moto2 podium having finished fourth on home soil at Silverstone earlier this season, said: “I guess you could say that we had a good day.
"The bike felt good from the start and the only issue was the track, which was a bit dirty and unpredictable in terms of grip. The white lines were also a bit dodgy, with the bike snapping sideways on me a couple of times when I ran over them.
"It was a good session, because I was out on my own for most of the time and able to try different lines through a lot of the corners. We tried a few things on the bike early on, before heading out towards the end of the session to set a fast time.
"The lap time came pretty easy and I felt really comfortable on the bike, so it looks good for this weekend. Now we need to focus on qualifying, where we have to continue to run at the front of the field."