Sparta Prague and Chelsea last met at the beginning of the Roman Abramovich era in 2003. The Blues won that tie 1-0 on aggregate courtesy of a win in Prague, a feat they are on course to repeat this time around.
Oscar's first touch after coming on as an 82nd minute substitute gave Chelsea the advantage in a drab match, which showed exactly why the European champions are no longer in the continent's top competition.
Here are six things we learned from the Blues first ever Europa League game.
Oscar shows some love after scoring the winning goal.
Oscar scored two wonderful goals against Juventus in September and scored his sixth goal in seven European appearances against Sparta Prague. The youngster has thrived in the Continental Cup competitions but has struggled to carry that form over to the Premier League.
He has scored one goal in 23 appearances in the league where he has been better at tackling than converting chances. If this versatility is recognised and Oscar is allowed to play to his different strengths, the £25 million that Chelsea spent on his transfer will be their best investment in recent years.
Sparta Prague went into this match having not played a competitive match since a 0-0 draw with Atletico Madrid in the Europa League on Dec. 6. Their lack of match fitness showed in a dire tie where they tired dramatically in the second half.
There is sense behind the winter break of course. Not to be simplistic, but it gets very, very cold in the Czech Republic. The average temperature in Prague in December and January is minus 5 degrees Celsius (23 degrees Fahrenheit).
While it makes sense to stop the season until it is safer for the supporters and players alike, it means that teams are at a significant disadvantage in UEFA competitions, up against teams entering the latter stages of their domestic seasons who have been playing together on a weekly basis.
There is only so much work you can do on the training ground, and with the Blues now holding an away goal advantage, Sparta Prague have an uphill struggle ahead of them to reach the last 16.
The Chelsea defender picked up a yellow card in the first half and didn't learn from his mistake as a studs-up challenge nearly saw him sent off in the second half. If he can become more disciplined and improve his positioning, he won't need to make such rash tackles.
His luck is bound to run out soon, and with John Terry suffering an ongoing knee problem and David Luiz a defensive liability, Chelsea can ill afford to lose him from their back four.
Victor Moses and John Obi Mikel returned victorious from the African Cup of Nations, with Mikel having been named as man of the match in the final. They were unavailable for this match but will return to the squad to face Brentford in the FA Cup.
Moses' return will bolster the Chelsea attack which has been lacklustre in recent weeks. His pass set up Nigeria's winning goal, and he will be able to provide width and depth, allowing the likes of Juan Mata and Eden Hazard to move a little more freely.
Mikel offers the best option in a defensive midfield role as he will stay back and cover, allowing his partner to play a more attacking role. Chelsea have had real problems with positioning this season, and Mikel is one of the few players who is always where he is supposed to be. That stability will be key as the Blues try to salvage something from a miserable season.
The team performance showed how far Chelsea have fallen since their triumph less than 12 months ago. Not for the first time, they lacked desire and were content to just kick the ball around amongst themselves for much of the match.
They kept Sparta Prague at bay and Petr Cech was never really tested, but so many half chances fizzled out into nothing. There is a lack of desire, a lack of fight throughout the team, and it is only remedied at all when John Terry is in the side.
In the past, Chelsea could look to Frank Lampard to inspire the team to win, as he did in Munich, but while the saga of the non-existent contract extension rumbles on, even Super Frank cannot lift his teammates heads.
Demba Ba came to Chelsea in January to help solve their problems up front. Whilst he has undoubtedly gone some way toward doing this, the owner should have realised that he would be ineligible for the Europa League campaign. That leaves Fernando Torres as the only recognised striker.
Rather than belabour the problems with this scenario, Chelsea have the perfect opportunity to play Juan Mata as a false nine, easing the pressure on Torres by allowing him to play provider as well as increasing the goal threat. With no other options, this strategy must be worth a try.