Stuttgart took the initiative in the early stages, and it took a flying one-handed save from Daniel Batz to keep out Maximilian Mittelstädt’s stinging drive.
Deniz Undav was then inches away from connecting with Jamie Leweling’s floated cross, and Jeff Chabot’s exocet worked Batz again, as Stuttgart sought to take advantage of their 73% possession.
Mainz came closest to opening the scoring on 20 minutes, but Paul Nebel couldn’t quite direct his effort into the net.
The hosts had the ball in the net on the half hour, but referee Matthias Jollenbeck ruled it out for a tenuous foul on Stuttgart goalkeeper Alexander Nubel.
As they came more into the game, only Lee Jae-Sung would know how he missed a free header from inside the six-yard box, before redeeming himself a minute later and giving Mainz the lead with a towering header as the half edged towards half time.
Nubel produced a full-length save to keep out Kaishu Sano’s long-range effort at the start of the second half, and then spread himself well to keep out Sheraldo Becker’s shot after Mainz failed to take advantage of a three-on-two situation.
After Nubel went walkabout, Phillip Tietz somehow contrived to miss an open goal and, as his shot was cleared, Nebel then hit the post from the rebound.
They were made to pay with 14 minutes to play as a super Stuttgart move ended when Ermedin Demirovic powered home, and just a minute later, Undav ran clear from the halfway line to put the visitors into the lead.
The final moments of the match saw Mainz chasing shadows, but a lapse in concentration at the back for Stuttgart allowed Danny da Costa to sweep home an injury-time equaliser.
The point does neither side any favours, with Mainz still just two points above the bottom three, and Die Roten only two above RB Leipzig in the race to finish in the Champions League places.
Flashscore Man of the Match: Deniz Undav (Stuttgart)