Alex Palou continued his spring of speed by leading the first practice for the Sonsio Grand Prix on Friday morning on the Indianapolis Motor Speedway road course, but there were a few surprises behind him on the speed charts.

NTT INDYCAR SERIES championship leader Palou, who has won three of the first four races this season, topped the 80-minute session with a time of 1 minute, 9.9790 seconds in the No. 10 DHL Chip Ganassi Racing Honda. Three-time series champion Palou has won this race the last two years on the 14-turn, 2.439-mile road course.

SEE: Practice Results

Palou led a 1-2 result for Chip Ganassi Racing, with second-year driver Kyffin Simpson springing a surprise by ending up second at 1:10.0677 in the No. 8 Journie Rewards Chip Ganassi Racing Honda. Rookie Louis Foster continued the list of unusual suspects near the top of the charts, third at 1:10.1235 in the No. 45 Mi-Jack Honda of Rahal Letterman Racing.

Santino Ferrucci was fourth at 1:10.1545 in the No. 14 AJ FOYT RACING/SEXTON PROPERTIES Chevrolet, a strong showing by a driver better known for his prowess on the 2.5-mile IMS oval in the Indianapolis 500 presented by Gainbridge.

Second-year INDYCAR SERIES driver Nolan Siegel rounded out a surprising top five – minus Palou – at 1:10.1730 in the No. 6 Arrow McLaren Chevrolet.

A busy day for the 27-driver field continues with another practice at 1:10 p.m. ET today (FS2, FOX Sports app, INDYCAR Radio Network). Then NTT P1 Award qualifying will start at 4:35 p.m. ET (FS1, FOX Sports app, INDYCAR Radio Network).

Live coverage of the 85-lap race starts at 4:30 p.m. ET Saturday on FOX, the FOX Sports app and the INDYCAR Radio Network.