RB Leipzig couldn't get past a draw against San Sebastián's grueling defensive wall and must fear for a place in the round of 16 in the Europa League.
The fourth-placed Bundesliga team drew 2-2 (1-1) from Real Sociedad in the first leg of the second round on Thursday.
Christopher Nkunku (30th) and substitute Emil Forsberg (82nd/penalty) scored twice to equalize in front of 21,113 fans.
The guests from Spain, who surprised with their very defensive style of play, scored their goals through Robin Le Normand (8th) and Mikel Oyarzabal (64th/penalty).
RB coach Domenico Tedesco coached in his first international game with Leipzig in a light gray coat on the sidelines.
The 36-year-old took over as RB coach at the beginning of December, when the end of the Champions League was already certain.
However, Tedesco did not get off to a good start as hoped: after a cross from the left, Le Normand cleared the second post and scored to give the visitors an early lead.
But RB recovered quite quickly and got stuck in half of the guests, who built a tight block of five in their defence.
The Leipzig shots in the middle from the second row, like those from Kevin Kampl (23rd), were initially unsuccessful.
Nkunku did better with a header after a good cross from Angeliño – the equalizer made the stadium louder again.
Tedesco was missing his defense chief Willi Orban, who was out with mild cold symptoms.
After the Leipzig goal, however, the RB defense got less and less to do.
The offensive of the guests with Alexander Sörloth, who was loaned from RB, hardly appeared anymore, with goalkeeper Mathew Ryan there was even a time game to be seen early on.
Real Sociedad had not won any of the previous four guest appearances in Germany.
With the substitution of Benjamin Henrichs, Tedesco strengthened the wing game in the second half, the guests were still too compact in the center.
The Spanish sixth-placed play style, which was very wait-and-see for long stretches, made RB difficult.
Nkunku tries from a distance (54th).
A very clumsy handball by Josko Gvardiol after a corner from the guests then led to a penalty whistle according to video evidence.
Oyarzabal didn't miss the chance and scored uncompromisingly.
RB then pressed for equalization again, but played with little accuracy.
The penalty taken by Dominik Szoboszlai, who came on seconds earlier, helped: Forsberg, who was also on the bench, hit the bottom left corner to equalize in the closing stages.
However, the supposed winning goal a few minutes later didn't count: André Silva's goal (88') was called off because Henrichs, who provided the assist, was offside.