Washington - New Zealand's Scott Dixon captured pole position for the 101st Indianapolis 500 with a dramatic four-lap qualifying run on Sunday while Formula One star Fernando Alonso booked a second row start.
Dixon, who won his only Indy 500 crown in 2008 from pole, shocked even himself by driving his Honda-powered car around the 2.5-mile (4km) Indianapolis Motor Speedway oval at 232.164 mph (373.631 km/h).
He then watched rivals try in vain to bump him from the inside front row spot in next Sunday's IndyCar classic.
"When I saw that first lap (at 232.595mph) I was a little shocked myself," Dixon said.
"It feels damn good. But this was job one. The pole is its own race. The significance is big. But the most important thing is the race. Let's bring on next week."
Spaniard Alonso, a two-time F1 champion who will skip next week's Monaco Grand Prix to seek a chequered flag as an IndyCar rookie, settled for fifth at 231.300 and will open in the middle of the second row.
"This is the biggest race in the world," Alonso said.
"I felt that the first time I came here. Now getting up to speed, with all the fans, I feel it's even more amazing. I can't wait for next Sunday."
American Ed Carpenter was second at 231.664, edging US defending champion Alexander Rossi, the outside row one starter.
Alonso will be flanked in row two by Japan's Takuma Sato to the inside and American J.R. Hildebrand to the outside.
The 33-car field was filled in two sessions based upon Saturday times, the fastest nine on Saturday running for the pole and the others completing the last eight rows.
That's how American Ryan Hunter-Reay had the fourth-best run of the day at 231.442 but will only start on the inside of row four.
"It was crazy. It was white knuckle the whole time," he said. "It didn't feel like I took a breath."
Dixon's third career Indy 500 pole after 2008 and 2015 came after the team gambled and trimmed out downforce. It paid off but left Dixon on edge as he watched rivals attack his time, some nudging the outer wall with tires in their speed quest.
"This place is nerve wracking, especially when you see everybody going around, touching the wall," Dixon said.
"These extremes, the highs and lows, it's emotional. The emotions you get here are crazy."
That's how last-man Carpenter felt after failing to overtake Dixon.
"If you told me we would have done what we did I would have thought that would have been on the pole," he said. "But when I saw Dixon's time, I knew it was going to be hard to beat."
Alonso had the fastest morning practice time but diagnostic readings worried team leaders and they ordered an engine switch, which came in 90 minutes to beat a deadline, adding to the stress on Alonso.
"With everything that has happened today being among the top 5 is a dream!" Alonso posted on Instagram, adding, "15 days ago I would never have thought about fighting for the pole. Thanks to the whole team!! Now another week of learning and race next weekend."
Alonso said he felt there was more he could have gotten out of the car as he learns with every Indy lap.
"I felt a little more confident on the track," he said. "I think I they changed the engine in record time and the car performed well."
Australian driver James Davison, grandson of a four-time Australian Grand Prix champion, was named by car owner Dale Coyne to replace injured French racer Sebastien Bourdais, who underwent successful surgery after suffering multiple pelvic fractures and a broken right rib in a crash during a qualifying attempt Saturday.
The Honda-powered entry, which turned Saturday's fastest two laps above 231 mph, will start last after not posting a qualifying time.
Starting grid for next Sunday's 101st Indianapolis 500 IndyCar race after Sunday's final qualifying session with name, nationality and four-lap mph speed average (R denotes Indy 500 rookie):
1. Scott Dixon (NZL) 232.164 (373.631 km/hr)
2. Ed Carpenter (USA) 231.664
3. Alexander Rossi (USA) 231.487
4. Takuma Sato (JPN) 231.365
5. R-Fernando Alonso (ESP) 231.300
6. J.R. Hildebrand (USA) 230.889
7. Tony Kanaan (BRA) 230.828
8. Marco Andretti (USA) 230.474
9. Will Power (AUS) 230.200
10. Ryan Hunter-Reay (USA) 231.442
11. R-Ed Jones (UAE) 230.578
12. Oriol Servia (ESP) 230.309
13. Mikhail Aleshin (RUS) 230.271
14. Graham Rahal (USA) 230.253
15. Max Chilton (GBR) 230.068
16. Charlie Kimball (USA) 229.956
17. James Hinchcliffe (CAN) 229.860
18. Juan Pablo Montoya (COL) 229.565
19. Helio Castroneves (BRA) 229.515
20. Jay Howard (GBR) 229.414
21. Sage Karam (USA) 229.380
22. Josef Newgarden (USA) 228.501
23. Simon Pagenaud (FRA) 228.093
24. Carlos Munoz (COL) 227.921
25. Gabby Chaves (COL) 226.921
26. Conor Daly (USA) 226.439
27. R-Jack Harvey (GBR) 225.742
28. Pippa Mann (GBR) 225.008
29. Spencer Pigot (USA) 224.052
30. Buddy Lazier (USA) 223.417
31. Sebastian Saavedra (COL) 221.142
32. R-Zach Veach (USA) 221.081
33. James Davison (AUS) no time
Ok la crono. Con todo lo que ha pasado hoy estar entre los 5 primeros es un sueño! Hace 15 días nunca lo hubiera pensado estar luchando por una pole. Gracias a todo el equipo y ahora una semana más de aprendizaje hasta la carrera. _______________________________ Ok for the qualy. With everything that has happened today being among the top 5 is a dream! 15 days ago I would never have thought about fighting for the pole. Thanks to the whole team!! Now another week of learning and race next weekend. #indy500 #honda #mclaren