(CNN) -- Turkish international Gokdeniz Karadeniz stuck a second-half winner as Rubin Kazan claimed a shock 2-1 Champions League Group F victory over holders Barcelona at the Nou Camp.
Rubin Kazan celebrate their stunning 2-1 victory against European champions Barcelona at the Nou Camp.
Karadeniz netted with 17 minutes to go to earn the Russian champions their maiden win in the competition 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 out of the blue, and although Barca levelled 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.
Barca levelled three minutes after the interval when Xavi's chip over the Rubin defence was chested down by giant Swede Ibrahimovic on the edge of the area and with his next touch he drilled an unstoppable shot in off the far post.
The defending champions 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.
Barca twice came agonisingly close to equalizing in the closing stages as they hit the woodwork through Ibrahimovic and Yaya Toure, but Rubin held on for a stunning victory.
Meanwhile, Serie A leaders Inter Milan twice came from behind to earn a draw with Dynamo Kiev in an entertaining clash at the San Siro.
The visitors took a shock lead after just four minutes courtesy of a superb finish from Taras Mykhalyk.
Junior Gerson Magrao's woeful free-kick should have been cleared by any of the three Inter players on the edge of the area, but somehow found its way through to Mykhalyk and he swept the ball into the bottom corner off the post.
The home side levelled in the 35th minute with a rapid counterattack. Wesley Sneijder and Lucio combined to free Dejan Stankovic and his task was made considerably easier as goalkeeper Stanislav Bogush charged out of the area, leaving Stankovic to flick the ball into an empty net with the outside of his right foot.
However, Dynamo took the lead again just five minutes later when Lucio inexplicably headed into his own net from Magrao's corner.
Inter equalized again less than two minutes into the second half when Sneijder's outswinging corner was met by Walter Samuel, who superbly headed into the far corner from a difficult angle.
The result, Inter's third successive draw, leaves the Italian side bottom of the group with three points, but just a single point separates the four teams in what is the closest of the eight groups.
Elsewhere, Sevilla recorded a third successive victory, 3-1 at Stuttgart, to continue their perfect start in Group G.
The Spaniards went in front when Sebastien Squillaci met Adriano Correia's cross with a firm header into the top right corner in the 23rd minute.
They doubled their lead 10 minutes after the break when Jesus Navas finished from close-range after goalkeeper Jens Lehmann dropped Diego Perotti's cross.
Sevilla made it 3-0 in the 69th minute when Squillaci added his second of the night, heading in Ivica Dragutinovic's free-kick from six yards out.
Stuttgart pulled a consolation goal back when Elson's sweetly-struck free-kick from 30 yards out gave goalkeeper Herrera Javi Varas no chance in the 73rd minute.
Meanwhile, Rangers' Champions League hopes are in tatters after an embarrassing defeat to Romanian side Unirea Urziceni at Ibrox.
A second 4-1 home European defeat in succession leaves Rangers bottom of the group with one point from three games and facing the return game in Romania in a fortnight knowing only a victory will do.
Pedro Mendes' second-minute drive, which took a deflection off Unirea midfielder Ricardo Vilana before going in, gave the home side the perfect start.
However, in a bizarre night of football, the home side proceeded to concede four goals, two of them own goals, while missing a penalty at 1-1.
After Marius loan Bilasco equalized just after the half-hour mark, Steven Davis had a spot-kick saved by Unirea keeper Daniel Tudor.
Half-time substitute Kyle Lafferty then helped a Bruno Fernandes flick past Allan McGregor and into his own net before Lee McCulloch left goalkeeper McGregor stranded with a header just before the hour mark.
More woe followed when Pablo Brandan made it four to send the home fans heading to the exits with 25 minutes remaining.