Will Power edged out James Hinchcliffe to secure pole position for Sunday's IndyCar race at Barber.
The Penske driver's 1m08.3120s came with his first flying lap, although Hinchcliffe's reply was only 0.02 seconds slower.
But rather than taking another swing, the Canadian returned to the pits, and Power's time proved to be beyond the reach of any of his other rivals.
Ryan Hunter-Reay, who led both of Friday's practice sessions, will start from third after falling 0.08s short of his team-mate's time, with Josef Newgarden - who was punted out of the Long Beach race by Hunter-Reay two weeks ago - completing the second row.
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Scott Dixon will start from fifth alongside Helio Castroneves, who squandered his flying lap with a wobble onto the grass.
Among the upsets was Mike Conway stranding himself towards the back of the field after flat-spotting a tyre on his flying lap during the first segment.
It was also a tough afternoon for the non-Dixon Ganassis, as all three were eliminated before the final round, while KV Racing's Sebastien Bourdais was docked his two fastest laps for interference during phase two.
Another architect of his own demise was Marco Andretti, who was eliminated during the second segment.
"That one was on me," he admitted. "The team gave me the car, and I almost crashed it in Turn 12. That cost us the time we needed [to progress]."
Follow the MotoGP and IndyCar races as they happen on AUTOSPORT Race Centre Live from 17:30 UK time on Sunday April 27
Pos Driver Team/Engine Time Gap
1. Will Power Penske/Chevy 1m08.3120s
2. James Hinchcliffe Andretti/Honda 1m08.3409s +0.0289s
3. Ryan Hunter-Reay Andretti/Honda 1m08.4264s +0.1144s
4. Josef Newgarden Fisher/Honda 1m08.4702s +0.1582s
5. Scott Dixon Ganassi/Chevy 1m08.5151s +0.2031s
6. Helio Castroneves Penske/Chevy 1m08.6258s +0.3138s
7. Carlos Munoz Andretti/Honda 1m08.6388s Round 2
8. Juan Pablo Montoya Penske/Chevy 1m08.6453s Round 2
9. Marco Andretti Andretti/Honda 1m08.6634s Round 2
10. Simon Pagenaud Schmidt/Honda 1m08.8682s Round 2
11. Mikhail Aleshin Schmidt/Honda 1m09.1708s Round 2
12. Sebastien Bourdais KV/Chevy --- Round 2*
13. Sebastian Saavedra KV/Chevy 1m08.9674s Group 1
14. Takuma Sato Foyt/Honda 1m09.1451s Group 2
15. Carlos Huertas Coyne/Honda 1m09.0267s Group 1
16. Justin Wilson Coyne/Honda 1m09.2018s Group 2
17. Charlie Kimball Ganassi/Chevy 1m09.1941s Group 1
18. Graham Rahal Rahal/Honda 1m09.2228s Group 2
19. Oriol Servia Rahal/Honda 1m09.2935s Group 1
20. Ryan Briscoe Ganassi/Chevy 1m09.2722s Group 2
21. Mike Conway Carpenter/Chevy 1m09.8580s Group 1
22. Jack Hawksworth Herta/Honda 1m09.4201s Group 2
23. Tony Kanaan Ganassi/Chevy 1m09.5829s Group 2
* Fastest laps removed for qualifying interference