Wednesday saw the other 16 teams involved in this year's Champions Leagues make their bow and, while it took a bit longer than Tuesday's fare to get going, there were some shock results.
Chelsea were hoping to start their campaign in style at home to Basel, while Arsenal were facing a difficult proposition away in Marseille.
Barcelona hosted Ajax at Camp Nou, while perhaps the match of the night saw Napoli meet last year's runners-up Borussia Dortmund in Naples.
Click on for all the scores and analysis from all eight matches.
(stats via UEFA.com, GIFs via @FeintZebra, @TheScore or B/R own)
A late goal from Marco Streller completed a remarkable comeback from FC Basel, who beat Chelsea 2-1 at Stamford Bridge.
The Blues had taken the lead through Oscar—his sixth goal in just seven Champions League appearances—but were stunned as first Mohamed Salah finished off a remarkable passing move to equalise, before Streller sealed a shock three points with just nine minutes remaining.
Jose Mourinho walked off to the sound of boos around the ground after the shock defeat.
nly Basel, Barcelona and Charlton (on penalties) have beaten Chelsea at Stamford Bridge under Mourinho.
Two emerging Napoli heroes, Gonzalo Higuain and Lorenzo Insigne, grabbed the goals as the Italian side beat Borussia Dortmund in a game that saw Dortmund's manager Jurgen Klopp and goalkeeper Roman Weidenfeller both see red.
Klopp was incensed at officials for delaying Nevan Subotic's return to the pitch after an injury, with the defender watching from the sidelines as Higuain headed Napoli into an early lead.
Klopp's reaction earned him an early bath.
It would get worse for Klopp, however, as Weidenfeller was sent off shortly before halftime after handling outside the box as Higuain went through on goal.
That seemed to derail Dortmund, but it was not until Insigne stepped up and curled home a beautiful free kick that the points were sealed.
Juan Zuniga bundled in a late own goal to give Dortmund a glimmer of hope, but it did not prevent the Serie A contenders taking all three points.
Said Dortmund's Nuri Sahin, per UEFA.com:
All things considered, it was a deserved defeat. Napoli passed the ball well and we tried everything we could. Every defeat hurts, especially when you know that a win here would have been huge for our campaign.
I don’t think the players can be blamed today, Napoli simply are a quality side and when you are down one man, it is very difficult.
Theo Walcott and Aaron Ramsey both notched as Arsenal picked up a potentially key opening win against Marseille, who got a late consolation after receiving a soft penalty.
In another accomplished performance, Walcott opened the scoring with a rasping volleyed finish at the start of the second half, before Ramsey sealed the points with a run and (slightly deflected) finish.
Jordan Ayew then scored from the spot in injury time, after brother Andre was felled—a decision Arsene Wenger later disputed.
Arsenal enjoyed 52 percent of possession—no mean feat away from home in Europe—but created just 10 shots to the French side's 17, despite having Mesut Ozil in the side.
Nevertheless, victory was the most important thing, especially with Dortmund losing in the group's other match against Napoli.
"I believe it was important to get the first goal," Arsene Wenger said, per UEFA.com. "I thought Marseille had an excellent first half. We were a bit timid, but overall it was a victory of patience and experience even if we were not flamboyant."
It was a case of "anything you can do, I can match," as Lionel Messi scored a hat-trick in Barcelona's opening match—just as Cristiano Ronaldo did for Real Madrid 24 hours earlier.
Messi was his usual clinical self as he scored three of Barcelona's four goals, with Gerard Pique getting the other as Gerardo Martino's side cruised against an Ajax side that share much of their mentality.
Messi's opener was perhaps the pick of his bunch—a measured free kick that bounded in off the far post. Two clever slotted strikes followed, between which Pique headed home from a deep cross.
Chasing a consolation their endeavour probably deserved, Kolbeinn Sigthórsson saw his penalty kick saved by Victor Valdes after Javier Mascherano committed a foul.
Ajax were occasionally impressive—testing Valdes six times in the 90 minutes—but were overwhelmed by Barca's evident quality. Nevertheless, head coach Ronald de Boer was disappointed, telling UEFA.com:
A second-half rally from Atletico Madrid was enough as the Spanish side defeated Zenit St. Petersburg, 3-1, in front of their home fans at Estádio Vicente Calderón.
Expensive striker Hulk equalised for the visitors in the first half after Miranda had headed home from a corner, but Arda Turan (in fortuitous circumstances) and Leo Baptistao helped Diego Simeone's side eventually run away with the win.
Zenit won the possession battle at 54 percent, but managed to create only half as many chances, as the likes of Koke and Baptistao impressed with their vigour.
Simeone told UEFA.com:
If Celtic did not feel unlucky enough after being drawn alongside AC Milan and Barcelona (let along Ajax), then it got a whole lot worse for them in this opening group-stage match.
Moments after Anthony Stokes saw his free kick hit the crossbar and bounce clear, the Scottish team could only watch on as Cristian Zapata's deflected 82nd-minute shot crept into the net (it was later put down as a Emilio Izaguirre own goal).
Milan had been somewhat woeful prior to that slice of luck, but that moment seemed to liberate them, Sulley Muntari sealing the three points as he bundled home after Fraser Forster had saved Mario Balotelli's near-perfect free kick.
Neil Lennon, somewhat unsurprisingly, was devastated, telling UEFA.com:
It needed an unusual goal to get things started, but Schalke eventually romped to a 3-0 win against Steaua Bucharest thanks to Julian Draxler's dynamic play.
It took 67 minutes for Schalke to find a breakthrough, and it came in unlikely circumstances. There looked to be little danger as Atsuto Uchida dinked a cross into the box toward no Schalke attacker, but a mix-up in the defence confused the Steaua goalkeeper as the ball passed him and nestled in the net.
Buoyed by that good fortune, Draxler then took control, setting up Kevin-Prince Boateng for Schalke's second before burying the third himself.
Steaua created 10 shots to Schalke's 13, but were punished for a little inexperience at this level.
Steaua’s head coach, Laurențiu Reghecampf, was upbeat, saying to UEFA.com: “We have to learn from these mistakes. They scored at their first goal opportunity. This happens in football when you make childish mistakes. We can beat Schalke in Bucharest.”
The final game of the day saw Porto scramble to a hard-fought victory over Austria Wien, thanks to Lucho Gonzalez's strike.
Gonzalez swept home from Danil's cross shortly after halftime, ensuring a fine start for the 2004 tournament champions.
Porto dominated possession—enjoying an almost unheard-of 65 percent throughout the contest—although that did not necessarily translated into chances. But it nevertheless provided the basis for victory.