Reigning Pro Mazda champion Santiago Urrutia set the pace in the final test day of the Indy Lights pre-season at Barber Motorsports Park, Alabama.
Urrutia, who graduates to Lights with Schmidt Peterson, edged a fellow rookie - Belardi's Felix Rosenqvist - by less than 0.02s in the second session.
Scott Hargrove, who is confirmed for St. Petersburg only, and Urrutia's teammate RC Enerson, who was the highest-placed of the drivers with at least a season of Lights experience, took third and fourth - and were the only drivers besides the leading duo to dip into the 1m12s margin.
The first session, meanwhile, had been topped by Ed Jones - albeit Hargrove came up just 0.015s short with a late attempt. Jones was the only driver in the field who then didn't improve his time in session two, but his earlier benchmark proved good enough for fifth overall.
Juncos, the team that took Spencer Pigot to last year's title, was headed by Kyle Kaiser, who placed third in the morning and sixth in the afternoon.
SPM's two drivers who are yet to confirm their participation in the 2016 Lights season - Andre Negrao and Scott Anderson - were ninth and 16th overall respectively.
Andretti's big-name signing Dean Stoneman was 14th in his first official session in the series and moved up to 10th in session two.
Finally, the biggest mileage of the day was recorded by third-year driver Juan Piedrahita, who took 12th after 115 laps.