Fernando Torres' Europa League hot streak continued as Chelsea advanced to the semifinals despite a 3-2 loss to Rubin Kazan at the Luzhniki Stadium in Moscow. Chelsea moved on by virtue of 5-4 aggregate.
Torres, who scored twice in the 3-1 first-leg win, struck his 19th of the season after four minutes, but thereafter Chelsea endured a difficult evening on the synthetic surface.
Three goals in 13 second-half minutes, two of them for Rubin, had Chelsea worried, as Ivan Marcano and Gokdeniz Karadeniz scored headers either side of Victor Moses' curled effort.
Bebras Natcho's 75th-minute penalty led to an anxious conclusion, but Chelsea held on to advance to Friday's semifinal draw.
Rubin had already eliminated 2012 Europa League winners Atletico Madrid and was seeking to add the Champions League holders to its list of conquests, but Chelsea did just enough in their 58th game of the season.
Manchester City is next for the Blues in Sunday's FA Cup semifinal and there will be changes for Wembley, where an improvement is required if the Londoners are to continue their trophy defense.
Chelsea captain John Terry was far from his best on a collectively shaky defensive display against inspired opponents in their temporary home, but it was an altogether unconvincing display from the visitors.
The second leg was moved to the Russian capital because of freezing temperatures in Rubin's home region of Tartarstan.
Chelsea had been grateful for a shorter journey even though the Luzhniki Stadium holds painful memories.
It was the Blues' second visit to the venue since their Champions League final penalty shootout defeat to Manchester United in 2008 and their October 2010 defeat of Spartak Moscow.
The location made for a surreal atmosphere in a third-full stadium, with many of those watching Russian Chelsea fans.
Nathan Ake made his second senior start as one of seven changes from the Sunderland win, while Paulo Ferreira, who required treatment in the opening skirmishes, featured at left-back due to the absences of Ashley Cole (hamstring) and Ryan Bertrand (illness).
Ake's inclusion in defensive midfield alongside Ramires allowed Frank Lampard to play behind Torres as one of Chelsea's three attacking midfielders.
It was Lampard's first-time lofted through ball which sent Torres clear with the Blues' first attack and the Spaniard showed the finishing instinct which has so often been lacking during his spell at Stamford Bridge since his £50million transfer from Liverpool.
Torres' first touch saw him lift the ball over the advancing goalkeeper Sergei Ryzhikov for it to bounce once and go into the net.
The goal meant Rubin needed three to force extra-time, but it was Chelsea, which almost went further in front soon after.
A mistake by Oleg Kuzmin allowed Moses, who also scored in the first leg, through, but he shot tamely at Ryzhikov.
Chelsea was prepared to sit and play on the counter-attack, with Ake and Ramires effective at breaking up play as Rubin went forward.
On the few occasions when the defense was breached, Rubin failed to trouble Petr Cech in goal.
Jose Rondon flashed a shot wide and a tricky run by Alan Kasaev led to a shot by Roman Eremenko, which deflected off Ake, but Cech, wearing leggings to guard against the cold and synthetic surface, saved to his left.
Cech had to be alert as the first half came to a close when Bebras Natcho's lofted pass found the darting run of captain Karadeniz, whose shot was well-saved by the Chelsea goalkeeper.
Rubin equalized six minutes into the second half when Pablo Orbaiz's cross was met by Marcano, who rose above Ramires to direct a powerful header into the net.
Fortunately for Chelsea its response was almost immediate.
Ramires won the ball from Orbaiz and laid it off to Lampard, who found Moses.
The Nigeria international played a one-two with Ramires and curled a shot into the top corner.
Rubin would not buckle, though, and continued to press forward.
Cristian Ansaldi took Cesar Azpilicueta to the byline and crossed for the late-running Karadeniz, the smallest player on the pitch, to power a header beyond Cech.
Marcano struck the outside of the post with a header from another Ansaldi cross as Rubin again demonstrated Chelsea's defensive fallibility.
Azpilicueta fouled Aleksandr Ryazantsev to grant Rubin a second penalty of the tie, which, like at Stamford Bridge, Natcho converted.
Rubin continued to forge on, with Ansaldi playing as an auxiliary left-winger. He found Rondon, who headed straight at Cech.
Time and again Chelsea had to repel Rubin attacks in the closing moments and reinforcements were called as Branislav Ivanovic was brought on for stoppage time as the Blues advanced.