Jurgen Klopp's in-form Liverpool head into the second leg of their Champions League last-16 clash with Porto with one foot firmly planted in the next round, having won the reverse fixture 5-0.
To stand any chance of overturning that seemingly insurmountable deficit, the Portuguese outfit will have to do something they have never accomplished before: beat an English side in European football's elite competition away from home, and beat them resoundingly.
Liverpool
© SilverHubLiverpool are firing on all cylinders at the moment, inspired by the goalscoring feats of Mohamed Salah, the creativity of Sadio Mane and significant improvement across the pitch.
The Reds' convincing victory at the Estadio do Dragao is just one of their impressive wins during a run of form that has seen them go six games unbeaten in all competitions, winning five of those.
This purple patch has catapulted Klopp's side up to second place in the Premier League table and helped them stake a strong claim for the runners-up spot behind champions-elect Manchester City.
In Europe, the Reds have been consistent throughout their campaign, making it through the group phase unbeaten, a feat only Tottenham Hotspur and Barcelona have managed to equal.
Following their 5-0 win in the first leg of this fixture, Liverpool are the top scorers in this season's Champions League with a whopping 28 goals in total, 25 of which came in their last five European fixtures.
Highlights of their campaign so far include 7-0 drubbings of both Spartak Moscow and Maribor of Slovenia, and their thrilling six-goal draw away to Sevilla.
Only Bayern Munich can claim to have registered more touches inside the opposition's penalty area than Klopp's side in Europe this season, racking up 277 compared to the Reds' 271.
Mane has proved a key man for Liverpool in this term's competition, having scored six goals in his last three European matches, including a hattrick at Porto.
In terms of creativity, James Milner leads the way with an impressive six assists so far. Only Neymar and Ousmane Dembele have matched that tally in the past five years.
All signs point to Liverpool progressing to the quarter-finals. Not only have the Reds never lost by more than two clear goals at Anfield in the Champions League, no team in the history of the competition has ever overturned a 5-0 first-leg defeat.
Recent form: DWWDWW
Recent form (all competitions): WDWWWW
Porto
© OffsideSergio Conceicao's side have enjoyed a solid season domestically and are in a strong position to win their first league title since 2012-13, sitting top of the table with a five-point lead over Benfica.
Since their drubbing at the hands of Liverpool, Porto have won every one of their domestic fixtures, putting five past Rio Ave and Portimonense and recently edging out third-placed Sporting Lisbon 2-1.
The Portuguese giants started their Champions League campaign slowly, losing twice to Juventus and then to Besiktas before a run of one defeat in five helped them scrape through to the knockout stage for the first time in consecutive seasons since 2009-10.
However, they do not fare well in the knockout phase of the tournament, having lost their last four of these fixtures, scoring once and conceding 14 times.
England has not been a happy hunting ground for Porto in the Champions League either, with Conceicao's team failing to win there on the last 12 occasions, drawing twice and losing 10 times.
Their defeat to Liverpool in the previous leg was the biggest ever away victory for an English side in the knockout rounds.
Recent form: WLWDWL
Recent form (all competitions): WLWWWW
Team News
© OffsidePorto are likely to be without a string of key players for the visit of Liverpool, as Alex Telles, Moussa Marega and Tiquinho Soares all picked up knocks against Sporting at the weekend.
Danilo also remains out for the hosts, meaning striker Vincent Aboubakar, who returned to the starting XI in their last domestic fixture, is likely to lead the attack.
Klopp has hinted that he will make two or three changes to his starting XI for the second leg, and either Gini Wijnaldum or Ben Woodburn could be handed game time after missing Liverpool's 2-0 win over Newcastle United last weekend.
Nathaniel Clyne and Adam Lallana are also pushing for starts, while midfielder Emre Can could return to Champions League action after missing the first leg through suspension.
Top scorer Salah, meanwhile, could be rested as the race for the Premier League runners-up spot heats up.
Porto possible starting lineup:
Casillas, Ricardo, Reyes, Marcano, Almeida, Herrera, Sergio, Otavio, Brahimi, Waris, Soares, Boubakar
Liverpool possible starting lineup:
Karius, Alexander-Arnold, Lovren, Van Dijk, Robertson, Henderson, Can, Milner, Lallana, Firmino, Mane
Head To Head
When Liverpool and Porto met for the first leg, goals from Salah, Roberto Firmino and a Mane hattrick helped the Reds to a landslide victory.
That result saw the Reds extend their unbeaten run against the Portuguese giants, having never lost in any of their five meetings, a run that includes two draws and three wins.
Their only previous encounter in the knockout stage of a European competition came in quarter-finals of the 2000-01 UEFA Cup, a tie Liverpool won 2-0 on aggregate on their way to lifting the trophy.
We say: Liverpool 3-0 Porto
Both of these teams are unbeaten since they met in Portugal for the first leg and all signs point to a somewhat closer contest on the night this time.
Klopp is expected to rest a few key players, but that is offset against Porto's sizeable list of absentees.
However, free-scoring Liverpool have enough quality among their ranks to add to that five-goal aggregate scoreline and progress to the quarter-finals in style, regardless of which team Klopp puts out.
