Kick-off was delayed at the Ramon Sanchez-Pizjuan due to a fault in the new football being used - with LaLiga becoming the first league to use Connected Ball Technology. However, after an embarrassing false start, the game eventually got underway without the tech being deployed.
Once play was finally moving, Rayo made a perfect start, opening the scoring inside four minutes thanks to some comical defending by Sevilla.
A mix-up between Arouna Sangante and Odysseas Vlachodimos on the edge of the box allowed Alvaro Garcia to steal possession and poke into an empty net.
Sevilla, who survived by a point in a dramatic relegation battle in LaLiga last season, looked to be struggling once again here, failing to register a shot on target in the first half.
A laboured first period exploded into life late on with Rayo having an Isi Palazon header ruled out for a foul in the build-up, before VAR handed the visitors a reprieve less than 10 minutes later.
Sevilla were awarded a penalty after Augusto Batalla collided with Isaac Romero in the box, but after review, referee Ricardo de Burgos reversed his decision.
Sevilla needed to improve upon the restart, and they got off to a flyer - having two early penalty shouts - with the second resulting in a spot-kick being awarded after Miguel Sierra was brought down in the box by Garcia.
Jon Guridi dispatched his penalty with aplomb, burying it into the bottom-right corner to mark his Sevilla debut with a goal.
Armed with all the momentum following the equaliser, the hosts failed to build on that as Rayo brilliantly soaked up the pressure, but they too struggled to replicate the same attacking intent shown in the first half and failed to register an effort on target in the second period.
The home side were reduced to 10 men late on after Kike Salas was given a straight red card for a reckless challenge on Jorge de Frutos.
Rather than make their man advantage count, Rayo were caught on the break, and Sevilla were awarded a spot-kick for a third time on the night after Florian Lejeune tripped Robbie Ure, and Peque emphatically buried his penalty to claim all three points and hand their hosts a first win on the opening weekend since 2021/22.
Flashscore Man of the Match: Odysseas Vlachodimos (Sevilla)
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