Liverpool will be hoping for a calmer European night this time around when they travel to Porto on Tuesday.
Jurgen Klopp's men had to come from behind to snatch a 3-2 win over AC Milan in their first fixture, and they maintained that level of chaos in the Premier League as they fell to a 3-3 draw with newcomers Brentford on Saturday.
They're up against a Porto side who are yet to taste defeat in any competition this season but could really do with a win, having been held to a 0-0 draw with Atletico Madrid last time out.
Here's all you need to know about this one.
How to watch Porto vs Liverpool on TV/live stream
When is it being played? Tuesday 28 September, 20:00 (BST)
Where is the match being played? Estadio do Dragao, Porto
What TV channel is it on? BT Sport (UK), Paramount+ (US), DAZN (Canada)
Referee? Sergei Karasev (RUS)
VAR? Bastian Dankert (GER)
Porto team news
Porto are in the midst of a defensive crisis. Chancel Mbemba is suspended after his red card against Atleti, while Pepe is likely to miss out after being forced off injured in the same game. Ivan Marcano will definitely feature and should be joined by Fabio Cardoso.
In midfield, former Liverpool man Marko Grujic is expected to start.
Liverpool team news
Liverpool's injury woes are in midfield. Harvey Elliott has been joined on the treatment table by Thiago and Naby Keita, so there aren't too many opportunities for Klopp to rotate here.
Right-back Trent Alexander-Arnold also hasn't travelled with the squad, and with Neco Williams short of fitness, we could be seeing James Milner at the back again.
That's hardly ideal as Liverpool must prepare for a Premier League meeting with Man City at the weekend, so Klopp may look to give fringe players like Kostas Tsimikas and Takumi Minamino the chance to impress.
Porto vs Liverpool predicted lineups
Porto: Costa; Corona, Cardoso, Marcano, Wendell; Otavio, Oliveira, Grujic, Diaz; Taremi, Martinez
Liverpool: Alisson; Milner, Matip, Gomez, Tsimikas; Henderson, Fabinho, Jones; Salah, Firmino, Minamino
Porto vs Liverpool head-to-head record
This will be the ninth meeting between these two sides, and Porto are still on the hunt for their first victory.
Their last meeting came in the 2018/19 quarter-final. Liverpool won 2-0 at Anfield before heading to Portugal and romping to a 4-1 victory thanks to goals from Sadio Mane, Mohamed Salah, Roberto Firmino and Virgil van Dijk.
They were just as dominant the year before, when a 0-0 draw and a 5-0 win gave Liverpool a comfortable triumph in the last 16.
Porto vs Liverpool score prediction
This could be a really tricky one for Liverpool. Porto have begun the season in impressive form and usually know how to put in a good performance under the European lights.
Klopp's men have been dominant themselves, but recent wobbles against Milan and Brentford have made Liverpool feel somewhat mortal and Porto will be looking to capitalise on that uncertainty here.
Ultimately, the Reds should have enough about them to win this. Porto's defence is weaker than normal and that should present the visitors with a good chance of sealing three points.
Prediction: Porto 1-3 Liverpool