The Frenchman lapped the former Portuguese Grand Prix venue in 1m 25.321 seconds, as he beat his batch of runners in the opening 15-minute session.
Gommendy will start alongside Carlin Motorsport's Andreas Zuber, who topped his batch of runners in the second session.
Because the average of the fastest times in both sessions was outside the permitted limits to determine the grid on qualifying times alone, the runners in both sessions will start parallel on the grid tomorrow.
Runaway championship leader Kubica will start third, and should results go his way he could be crowned champion three races early. The Polish driver has a 44-point lead over Spaniard Adrain Valles, with 17 points maximum available for each race.
Double race winner Marcus Winkelhock will start fourth after finishing second to Zuber in the second session.
That session was interrupted with two red flags - the first to recover Milos Pavlovic's stricken GD Racing machine - and the next to recover Fabio Carbone's car from a gravel trap.
Nicolas Prost, son of four-time Formula One World Champion Alain, had a troubled session, going off the road twice on route to 24th on the grid.
Pos Driver Team Time 1. Tristan Gommendy KTR 1:25.321 2. Andreas Zuber Carlin Motorsport 1:25.625 3. Robert Kubica Epsilon Euskadi 1:25.529 4. Markus Winkelhock Draco Multiracing Usa 1:26.008 5. Felix Porteiro Epsilon Euskadi 1:25.710 6. Adrian Valles Pons Racing 1:26.055 7. Colin Fleming Jenzer Motorsport 1:25.956 8. Simon Pagenaud DHG Saulnier Racing 1:26.393 9. Patrick Pilet GD Racing 1:26.011 10. Fabio Carbone Eurointernational 1:26.412 11. Will Power Carlin Motorsport 1:26.020 12. Jaap Van Lagen KTR 1:26.736 13. Christian Montanari Draco Multiracing Usa 1:26.204 14. Celso Miguez Pons Racing 1:26.863 15. Fernando Rees Interwetten 1:26.240 16. Damien Pasini Cram Competition 1:27.055 17. Benjamin Hanley Cram Competition 1:26.389 18. Matteo Pellegrino RC Motorsport 1:27.136 19. Ryo Fukuda DHG Saulnier Racing 1:26.609 20. Pastor Maldonado Dams 1:27.140 21. Ryan Sharp Jenzer Motorsport 1:27.148 22. Matteo Meneghello Eurointernational 1:27.770 23. Davide Rigon Victory Engineering 1:27.463 24. Nicolas Prost Dams 1:28.485 25. Giovanni Tedeschi RC Motorsport 1:27.561 26. Ivan Bellarosa Avelon Formula 1:28.805 27. Mehdi Bennani Avelon Formula 1:29.710
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