Rene Binder claimed his first Formula V8 3.5 pole, leading a Lotus one-two in qualifying for race one at Austin.
The Austrian, who suffered two disappointing rounds at the previous Nurburgring and Mexico City events, was fastest in second practice and maintained that form in Thursday's first qualifying session.
Binder, who is racing with a new engine this weekend after his previous one failed in Mexico, recorded a best time of 1m49.764s to edge out team-mate Pietro Fittipaldi by 0.168 seconds and claim a maiden pole in the series.
Current championship leader Fittipaldi was the only other driver to dip below the 1m50s marker as he set a 1m49.932s.
His time, set on the final lap, knocked Egor Orudzhev off the front row.
The Russian's penultimate lap was ruined by a yellow flag at Turn 19 after he had recorded the session's best time in the middle sector.
Alex Palou will join Orudzhev on the second row for Friday's opening race.
The Teo Martin driver was fastest for a time with his best of 1m50.083s, but Palou could not find the pace on his final run to unseat the trio ahead.
Fifth went to second place man in the championship Matevos Isaakyan, who could not match SMP Racing team-mate Orudzhev or Lotus pair Binder and Fittipaldi and ended up 0.384s off the pace.
Konstantin Tereschenko, who claimed his maiden podium in Mexico City, will start the first race at the Circuit of the Americas from sixth.
The fourth row will be occupied by the Fortec Motorsport duo of Alfonso Celis and Diego Menchaca, while Yu Kanamaru, Roy Nissany and Giuseppe Cipriani completed the 11-car field.
The heat that affected drivers in Thursday's earlier practice sessions did not relent in qualifying, despite the session being held in the evening.
Track temperatures reached 43 degrees during the 30-minute session, with a number of drivers commenting that the high-speed corners in the first sector were particularly difficult in the heat.
|3||Egor Orudzhev||SMP Racing by AVF||1m50.028s||0.264s|
|4||Alex Palou||Teo Martin Motorsport||1m50.083s||0.319s|
|5||Matevos Isaakyan||SMP Racing by AVF||1m50.148s||0.384s|
|6||Konstantin Tereschenko||Teo Martin Motorsport||1m50.633s||0.869s|
|7||Alfonso Celis||Fortec Motorsports||1m50.756s||0.992s|
|8||Diego Menchaca||Fortec Motorsports||1m51.169s||1.405s|
|9||Yu Kanamaru||RP Motorsport||1m51.281s||1.517s|
|10||Roy Nissany||RP Motorsport||1m51.489s||1.725s|
|11||Giuseppe Cipriani||Il Barone Rampante||1m54.157s||4.393s|