Gokdeniz Karadeniz stuck a second-half winner as Rubin Kazan claimed a shock Champions League victory over reigning European champions Barcelona at the Nou Camp.

Karadeniz netted with 17 minutes to go to earn the Russian champions their first win in Group F and inflict a first competitive defeat over Barcelona since May.

It was also the first European defeat Pep Guardiola's men had suffered since losing at home to Shakhtar Donetsk last December having already qualified for the last 16.

An upset had been on the cards from the opening two minutes when Rubin took the lead through Alexander Ryazantsev's long-range piledriver, and although Barca levelled up through a fine Zlatan Ibrahimovic goal just after half-time, it was the visitors who went on to claim a memorable victory thanks to Karadeniz.

The result meant Rubin joined Barca on four points in Group F, with Dynamo Kiev on the same number following their 2-2 draw with Inter Milan, who have three points.

Some of the fans at the Nou Camp probably had not even taken their seats when Rubin claimed a shock lead through Ryazantsev with just over a minute on the clock.

There appeared little danger when the ball ran loose 35 yards from goal but Ryazantsev had other ideas and his first-time strike fizzed past Victor Valdes into the near top corner of the net.

That was the first time Barca had fallen behind in either Europe or the Primera Division this season, and whether it was a mixture of surprise or Rubin getting plenty of men behind the ball, the home side found it hard to get going in the remainder of the first half.

Ibrahimovic had two efforts that were saved by Sergei Ryzhikov but the Rubin keeper would have been disappointed if he had let either in, while Dani Alves' 25-yard effort hit the side-netting when a foot to the left would have brought a certain goal.

Ryzhikov had to work harder to save further efforts from Pedro Rodriguez and Lionel Messi but otherwise the visitors successfully kept their hosts at bay before the break, whilst they might even have netted a second goal themselves after winning a dangerous free-kick 20 yards out but Valdes was equal to Karadeniz's curling shot.

It was a frustrating period for Barca, but they needed just three minutes of the second half to get that out of their system as Ibrahimovic scored a fine equaliser.

Xavi's chip over the Rubin defence was chested down by the giant Swede on the edge of the area and with his next touch he drilled an unstoppable shot in off the far post.

The home supporters must have felt that would be the catalyst for a much improved performance by their side, but hard-working Rubin refused to capitulate and they made it just as difficult for Barca as they did before the break.

Pedro went close for the Spanish champions while Ibrahimovic saw a free-kick whistle just past the post.

Barca continued to push for an opening, but they were left shellshocked for the second time in the match when Rubin retook the lead through Karadeniz - and this time there was no way back for the Catalan giants.

A quick break by the Russian side resulted in Alejandro Dominguez putting Karadeniz through on the right of the area and the Rubin forward left Valdes with no chance with a well-struck effort into the far corner of the net.

That proved to be the winning goal, although Barca twice came agonisingly close to equalising in the closing stages as they hit the woodwork through Ibrahimovic and Yaya Toure.

Alves and Messi combined to give Ibrahimovic his chance but his volley from near the penalty spot crashed against the crossbar, and then in the final minute of injury time Toure headed Xavi's corner against the post as Barca slumped to a rare defeat.

Teams:

Barcelona Valdes, Dani Alves (Busquets 90), Marquez (Keita 80), Pique, Abidal, Toure Yaya, Xavi, Iniesta,Messi, Ibrahimovic, Pedrito (Bojan 66).

Subs Not Used: Pinto, Puyol, Maxwell, Jeffren.

Booked: Iniesta, Dani Alves.

Goals: Ibrahimovic 48.

Rubin Kazan Ryzhikov, Salukvadze, Sharonov, Cesar Navas, Ansaldi, Kaleshin, Noboa, Semak (Murawski 43), Ryazantsev (Kasaev 84), Karadeniz (Popov 90), Dominguez.

Subs Not Used: Revishvili, Bystrov, Gorbanets.

Booked: Murawski, Ansaldi.

Goals: Ryazantsev 2, Karadeniz 73.

Att: 52,000

Ref: Laurent Duhamel (France).