CLICK: Full qualifying results for race 2
Helio Castroneves will start the second race of the Shell and Pennzoil Grand Prix of Houston doubleheader from pole position on Sunday afternoon, after managing to pip Simon Pagenaud to the top spot by just 0.0260s.
However Pagenaud will start one row back on the grid behind his Schmidt Peterson Motorsport team mate Mikhail Aleshin, who was fastest in the first group in qualifying on Sunday morning.
The format for deciding the race 2 starting grid differs from the three-round elimination format used for race 1. Instead, the drivers are split into two groups and get 12 minutes apiece of track time to set their fastest laps. The driver with the fastest time gets pole, while the quickest driver in the other group gets to line up in second place.
Aleshin paced the first group with a time of 1:00.2493s (97.634mph) on the 1.634-mile, 10-turn temporary street circuit, five hundredths of a second faster than Graham Rahal who rebounded from his unfortunate finish to Saturday's race 1 to pick up a second row start for Sunday, while Justin Wilson will line up immediately behind Rahal on row three.
However the times in Group 1 had all been significantly slower than the previous day's equivalent session, and so it was no surprise when Group 2 went considerably faster with seven cars all dipping below the one minute mark.
For a time it looked as though Pagenaud had got the top spot locked up, which would have made it an all-Schmidt Peterson Motorsport front row and Pagenaud's second successive pole; but in the final seconds remaining in qualifying, Penske's Helio Castroneves managed to dig deep to set the best time of the group and thereby lock up the pole position for the 40th time in his IndyCar career.
"It's the right place to start and the right car to start because it carries the race sponsor," said Castroneves, who also won pole earlier this season for the first race of the Detroit doubleheader.
That means Castroneves will line-up alongside Aleshin for the rolling start in race 2, and gives the Brazilian his best opportunity to capitalise in the championship on further misfortune for his Penske team mate Will Power. The Australian, usually so formidable on street and road course races, will start back in 18th position on the grid for the second time this weekend.
"Another hard day. Just really puzzled as to what we are lacking here in qualifying at Houston," admitted Power. "We'll have to go to work and come up with a strategy that we can use to get toward the front."
There were no red flag stoppages to either group in qualifying, but Josef Newgarden was docked his fastest two laps in the session after it was deemed that he had obstructed one of Juan Pablo Montoya's flying laps. Newgarden will now start from the back row of the grid, while Montoya will start from 14th position.
It wasn't a great start to the day for Andretti Autosport's Marco Andretti, who as well as only managing to put himself into 16th place on the grid also learned that he was to be fined and put on probation for failing to heed directions from race control during Saturday's race.
Andretti had already been handed a drive-thru during the race for failing to heed blue flags and allow then-race leader Takuma Sato get by early in the race, but IndyCar officials have now added a $2,500 fine and a three-race probation on top. The team has also been fined $2,500 over the incident.
The green flag for today's race is at 2.45pm US Central Time (8.45pm BST), and it will be shown live in the UK on ESPN.
Full qualifying results for race 2