Kazan - Russian champions Rubin Kazan put up a stunning defensive display here on Wednesday to hold Champions League holders Barcelona 0-0.
The draw means that should Kazan finish on the same amount of points as Barcelona in Group F for second place they would go through to the knockout stages instead of the Catalan giants on the head-to-head rule, as they beat Barcelona 2-1 in the Nou Camp.
Kazan and Barcelona are both on five points after four matches.
Dynamo Kiev, who are on four points, host runaway Serie A leaders Inter Milan, who have three points, later on Wednesday.
Zlatan Ibrahimovic gave Kazan an early warning with a shot that hit the post after a fine ball by Andrea Iniesta, who had started on the left wing with French veteran Thierry Henry on the bench.
Barcelona, playing in what was described by coach Pep Guardiola as the coldest conditions he had ever experienced, did all the pressing.
Xavi went close with a cheeky chip in the 20th minute and a minute later Lionel Messi forced his way into the box after seizing on a knockdown from target man Ibrahimovic, but goalkeeper Sergei Ryzhikov got down to snaffle the ball.
Kazan initially did little to trouble Barcelona goalkeeper Victor Valdes and only forced their first corner in the 25th minute but it was cleared with little trouble by the visitors' defence.
However, Valdes was forced at last into making a save in the 41st minute as Eric Abidal went missing and midfielder Aleksandr Ryazantsev - who scored in their first meeting - cut in and fired in a rasping shot which the Barcelona 'keeper did well to get down to.
Barcelona went down the other end and almost took the lead themselves as a nicely worked free-kick saw Ryzhikov get down and block Iniesta's shot with his legs.
The Catalan side were again the ones to pose the questions at the beginning of the second half, with Ivory Coast international midfielder Yaya Toure firing in a shot from well outside the area that Ryzhikov spilled, but a defender was on hand to kick it clear.
The ever lively Iniesta was next to try his luck but having worked his way into the area he was quickly surrounded by five Kazan players and his shot went just wide of the post.
In a bid to add a sharper edge up front Kazan sent on their star striker Aleksander Bukharov - who missed their first meeting because of a hand injury - in the 62nd minute.
Bukharov showed his class from the moment he came on, twice breaking free, but he was to be denied on both occasions by the impressive Valdes and three minutes from time he rose magnificently at the near post only to see his header flash over the bar.
Henry came on for the final 10 minutes but failed to shine as he missed with both chances that came to him.