With no one else lining up for a qualifying run, the track was then opened up for practice runs as teams tried out their latest set-up changes, unless and until another qualifier made themselves known.
If no further qualifiers materialise, then the session will end in a little over 90 minutes for a half hour hiatus before the pole shootout.
Update at 6.37pm BST (1.37pm Indiana time):
Josef Newgarden shrugged off the crash of his team mate Bryan Clauson to post a laptime of 224.677mph to become the fastest of the Honda runners. Ana Beatriz will be less than thrilled with 223.920mph in the Andretti Autosport Chevy despite being a provisional seventh place.
Ryan Briscoe kept up the strong showing of the Penske cars with an average of 225.078s. He agreed with James Jakes that the track is getting increasingly slick as temperatures climb, and that the earlier runners had the best of it unless someone lucks into a period of cloud cover.
Tony Kanaan's first lap of the session has been deleted after the #11 failed post-qualifying tech inspection for being underweight, the team having forgotten to add the requisite weight ballast.
Ed Carpenter's run of 220.377s puts him in P14 (slowest runner to this point) but there's a remarkable 4mph drop off between the first and last laps of his four-lap run. "That was awful," he tells the media afterwards. "I"m really angry."
Michel Jourdain Jr. goes out right after and posts an average lap speed of 222.893mph (P12), a nice rebound after his Friday engine fire. Takuma Sato does better than that with a 223.392s, before EJ Viso opens KV Racing's account with an average lap speed of 224.422s to go sixth, followed by JR Hildebrand posting 223.422mph to slot in ahead of Sato outside the top ten.
After Simon Pagenaud (222.891mph), James Hinchcliffe went to the top of the speed charts with a four-lap average 225.746mph, 0.347s ahead of former polesitter Will Power. Hinch's run included a lap that was the first to exceed 226mph so far on Saturday; he was carrying with him a pair of the late Greg Moore's red gloves with him in the car.
Marco Andretti posts a slightly underwhelming aggregate time of 224.680mph to slot into sixth, followed by the 2011 polesitter Alex Tagliani setting a 224.000mph time to settle into ninth position. Mike Conway then sets a time of 223.160mph.
That completes the first run through the qualifying order, with 23 cars having set times and 26 having been out on track. Some drivers - including de Silvestro, Legge, Sebastien Bourdais, Jean Alesi and Rubens Barrichello - dropped out of the initial qualifying order and have yet to set a time. A little under half the five-hour Pole Day qualifying session remains. Cars now run in the order in which they enter the pre-qualifying inspection line.