Chelsea entered their round-of-32 match against Sparta Prague holding a 1-0 aggregate lead from the first leg. Mikel John Obi replaced Frank Lampard in the starting 11, while Branislav Ivanovic and Ashley Cole were rested, with Cesar Azpilicueta and Ryan Bertrand taking their places.
Despite a promising start by the hosts, the Czech side levelled the tie after 17 minutes at Stamford Bridge, baffling the European champions at the back. Chelsea should have gone on to put the tie to bed, but Sparta made sure that their best chances fell to Fernando Torres, ensuring a nervous finish for the Blues fans who braved the freezing temperatures.
Rafa Benitez made his only substitution after 68 minutes, replacing Oscar with Eden Hazard. As the tie looked to be heading to extra time and out of Chelsea's grasp, the Belgian made a determined run forward and powered his shot home from just inside the box with the last kick of the game.
Chelsea progress to face Steaua Bucharest in the last 16 of the Europa League, but they will need to be more efficient to avoid risking an upset.
These ratings assigned to players reflect the areas that they need to work on. Each player starts at 5/10, and points are awarded or subtracted based on attitude, work rate and effectiveness. For example, a defender gains more points than a forward if he scores, whereas he loses more points for goals conceded.
Petr Cech: 6.5/10
Sparta Prague were content to use Chelsea's tactics against them as they absorbed the pressure before attacking on the counter. Cech had very little to do throughout the game, but his positioning was poor for the goal conceded. Confusion amongst the back four led him to come off his line, and once the ball had been squared to David Lafata, he was unable to get back to cover.
He made six saves and found his man with 50 percent of his passes. Cech desperately needs to work on his distribution as well as his communication with the defenders in front of him. Against opposition with better match fitness, these two aspects of his game will undermine the efforts of the rest of the team.
Cesar Azpilicueta: 7/10
Azpilicueta has been one of the revelations of the season at Chelsea. Brought in from Marseille in the summer 2012 transfer window for £7 million, the 23-year-old has impressed with his all-round full-back play.
He made three interceptions against a well-organised, counter-attacking side and was also heavily involved in Chelsea's attack, finding his man with 81 percent of his passes. Despite making an error that led to a chance for Vaclav Kadlec after seven minutes, he recovered to block the shot and was key to Chelsea's efforts for the rest of the game.
A solid performance from the right-back, who is managing to keep Ivanovic out of the side on merit alone.
Gary Cahill: 6.5/10
Kadlec was able to outsmart Cahill for Sparta Prague's goal as the defender was caught flat-footed in the area. He dithered, and Kadlec was able to square to Lafata, who was unmarked and able to loft the ball into the net. However, Cahill went on to make three effective clearances and found his man with 87 percent of his passes.
He needs to improve his concentration and positioning because he tends to get caught out of position. His lack of awareness has contributed to Chelsea conceding more than 50 goals in all competitions so far in the 2012-13 season.
John Terry: 7/10
Terry's impact on the team cannot be measured in numbers alone. His constant communication with his teammates and passion for the club give the team an organised aura that they lack when he doesn't play. He was tracking back to cover Cech's lines when Lafata scored the aggregate equaliser but was unable to stop the shot from looping past him.
Chelsea's captain recovered from this, and 88 percent of his passes found their intended target. He made three effective clearances and two interceptions to keep the Blues in the hunt for the trophy that he has described as a must-win.
Ryan Bertrand: 7/10
Bertrand started the game at left-back and improved greatly over recent performances. His pass found Eden Hazard for the winning goal, and he performed his defensive duties well, making two interceptions and four effective clearances. He had the best passing accuracy of any Chelsea player at 94 percent and won two free kicks for his teammates.
If Bertrand continues to improve at this rate, he could provide a strong challenge for Ashley Cole's place in the starting 11 in the 2013-14 season.
Ramires put in another excellent performance in the pivot against Sparta Prague. Partnering with Mikel John Obi, he had the freedom to roam forward and had five shots at goal deflected off target, one of which came off Fernando Torres. He set up three chances for his teammates and linked up well with Oscar in particular.
As well as getting involved in the attack, Ramires made six tackles and had a passing accuracy of 82 percent. The stability provided by Mikel gives the Brazilian more confidence to relax and unleash his full potential, safe in the knowledge that there will be cover behind him should something go awry. This will undoubtedly be key to the rest of Chelsea's season.
Mikel John Obi: 7.5/10
Opinion on Mikel remains divided, but the difference in the defensive midfield when he is in the side is startling. Making his first start since returning triumphant from the Africa Cup of Nations, he made two tackles and five interceptions and made sure that the back four had adequate cover. His distribution was good with 12 accurate long balls and an overall pass success rate of 86 percent.
Every other midfielder employed in the holding role by Chelsea has a penchant for getting forward, but Mikel is content to stay back and defend. This stability has been sorely lacking at Stamford Bridge in recent weeks, and his return has come at a key time for the club.
After getting a late winner in the Czech Republic to give Chelsea the aggregate lead, Oscar replaced Hazard in the starting 11. Other than some wonderful linkup play with Ramires including a pass that led to a shot being turned onto the post by the Sparta defence, he went missing for long periods of the game. His passing accuracy was 76 percent, and he was replaced after 68 minutes by Eden Hazard.
Oscar is only 21 years old and has not yet found his best position on the team. He is superior to the other two amigos in the defensive side of his game, and if given time to work with Frank Lampard, he could make a very successful move to a box-to-box role.
Juan Mata: 7/10
Even supporters of clubs who are predisposed to hating Chelsea will admit that Juan Mata is in a class of his own. The joy he exudes when playing is infectious, and the skills he displays are sublime.
The latest of these tricks came in the first half when he received the ball in the box under pressure from two defenders. The ball had fallen behind him, and yet he somehow managed to flick it up and over his shoulder whilst turning to face the goal and skimming a shot just over the bar.
Six of his crosses found their target, and he set up four chances for his teammates. His overall passing accuracy was 79 percent, but his tenacity and skill so often make the difference in what has been a season of disappointment for Chelsea.
Victor Moses: 6.5/10
Victor Moses @VictorMoses
back in england had amazing couple of weeks thanks for all your support with nigeria lookin forward to playing for chelsea again now2013-2-12 13:47:49
Moses returned after a solid performance against Brentford in the FA Cup to add some width to Chelsea's attack. His passes found their target 79 percent of the time, and he made two tackles as well as having two shots and winning two aerial duels.
With Demba Ba cup-tied in the competition, it would make sense for Benitez to play Moses in a forward role with the Three Amigos in support, rather than persisting with Torres.
Fernando Torres: 6/10
When questioned on Torres' record of one goal (against Brentford) in his last 14 appearances, Benitez said that a striker should not be judged on his goal-scoring record. What criteria he would use instead are a mystery, but Torres' decline continues.
Against Sparta Prague, he had seven shots, one of which was on target but was a tame effort saved easily by the keeper. He conspired to block a shot from Ramires and had 42 touches of the ball, the lowest of any outfield player in the starting 11. Although he made four key passes to his teammates, his overall accuracy was 60 percent.
Eden Hazard: 7.5/10
Hazard came on as a second-half substitute for Oscar and emulated the Brazilian's impact from the bench in the first leg. He immediately won a free kick and gave a cutting edge to the attack. His 12 passes were 92 percent accurate, and he took the pressure off Mata in the attacking trio.
Hazard strode forward with purposeful determination, and his last-minute winner was a fabulous finish. His determination to prevent the looming extra time could prove crucial to a Chelsea side that have played an average of two games each week since the start of 2013.