Ludogorets' and Basel's battle to get out of the Champions League basement and into the Europa League will go to the sixth matchday after the teams could not be separated in Bulgaria.
The Swiss champions remain joint bottom with Ludogorets in Group A having only managed to take a single point -- against the same opposition, in September -- in this edition of the group stages.
This stalemate in Razgrad, which really ought to have swung in the visitors' favour given the industry of Luca Zuffi and Matias Delgado, leaves the route to continental football open to undeserving rivals.
Since reaching the last 16 two seasons ago Basel have struggled to make a dent in Europe's premier club competition and the best they can achieve this time around is a third-placed finish in their pool.
That does bring a run at the Europa League, though, so the Swiss Super League side set about their hosts with an obvious air of knowing they still have something to play for.
Zuffi got home goalkeeper Vladislav Stoyanov working before Mohamed Elyounoussi took aim from distance and, after the Norwegian missed the mark, Delgado's sighter was blocked.
On the half-hour mark Delgado went closer, clattering the crossbar from a free kick.
Ludogorets had absorbed the early pressure and seized their moment to bite back, Natanael setting up fellow Brazilian Cicinho for a solid effort that Cosmin Moti inadvertently deflected away.
An exchange of efforts before the break saw Zuffi come closest as Stoyanov got down to make a desperate parry, while Birkir Bjarnason was Basel's hero with a brave clearance on Jonathan Cafu.
The Iceland international was involved at the other end when play resumed, his shot from 12 yards fizzing wide, while Claudiu Keseru answered back with a wayward missile that veered left.
Sloppiness took hold until Elyounoussi managed to cut through the pack in the 76th minute and draw another impressive save from Stoyanov.
As Basel's desperation grew they threw bodies forward with Delgado forcing a block from Svetoslav Dyakov and the under-siege Stoyanov punching yet another Zuffi attempt to safety.
Try as they might, the Swiss could not get the ball over the line, but with Ludogorets visiting Paris Saint-Germain on the final day, Basel will perhaps prefer their chances of getting something from Arsenal.