Fontas and Vazquez were on target for the hosts...
Second-half goals from Andreu Fontas and Victor Vazquez condemned the former Russian champions to third place in Group D and also led the Blaugrana to their first victory over Rubin in four attempts.
Barcelona commenced the match with eight home-grown players in their line-up but with Xavi, David Villa, Daniel Alves and Pedro rested and Lionel Messi and Andres Iniesta on the bench, the team was mostly comprised of young players.
However, it was the Spanish champions who created the game's early chances, with first Thiago trying his luck with a right-footed shot from outside the Rubin box and then Maxwell failing to keep his attempt on target after being played on the left by Adriano.
Then on 13 minutes the hosts received an injury blow when Jeffren Suarez was forced off the pitch and was substituted by Víctor Vazquez. Moments later Barca goalkeeper Jose Manuel Pinto was forced into making a good save when Cristian Ansaldi's left-wing cross came dangerously close to being squeezed in at the near post.
A couple of minutes later Karadeniz Gökdeniz took an attempt on the Blaugrana goal for the Tatars from the edge of the box but failed to keep it on target.
The Russian visitors were exhibiting a distinct lack of urgency and on 26 minutes Pep Guardiola's side tested Sergei Ryzhikov when played through by Adriano, Thiago took a shot from outside the 18-yard box. However, he failed to get it past the Rubin custodian.
Seconds later Vitaliy Kaleshin squeezed a brilliant through ball past a host of Barcelona defenders down the left for Gökdeniz but the 30-year-old went for a shot himself in vain rather than cross it for Obafemi Martins in the middle.
There was precious little to entertain the Camp Nou faithful for the rest of the half as both sides went into the interval without looking impressive. with Barca having been forced to replace Bojan Krkic with Marc Bartra.
Barcelona had appeared the likelier of the two sides to break the deadlock and they did so just six minutes into the second-half. Thiago weaved his way into the Rubin box from the right and played a shot pass to Fontas, whose shot from just outside the six-yard area took a wicked deflection of Vitaliy Kaleshin and went past a helpless Ryzhikov into the net.
Minutes later the 21-year-old almost scored his second of the evening when he went for a long-distance shot but failed to keep it on target.
Four minutes after the hour mark, though, Kurban Berdyev's side should have equalised when Martins played Jerzy Rafal Murawski through on goal with a well-measured pass but the 29-year-old's attempt was easily saved by Pinto.
Messi had come on by then and started crafting his sorcery, his first shot going narrowly wide and he then left the entire Rubin defence in his wake only to have the final shot blocked.
Barcelona eventually bagged the second goal on 82 minutes when Adriano released Vazquez, who made no mistake in finding the target from 20 yards.
This is the first time in four attempts that Barcelona have registered a victory over Rubin Kazan, who now drop to the Europa League just as they did last season.