Chelsea's 6-0 romp at St Mary's on Saturday proved they can win big on the road - but it's one thing doing it at Southampton, quite another at Real Madrid.
Chelsea have given themselves an absolute mountain to climb in the Bernabeu following their 3-1 Champions League defeat by Real Madrid in last week's home leg of their quarter-final.
Indeed, it's such a big task that Thomas Tuchel immediately downplayed the likelihood of the mother of all comebacks in the Spanish capital as out of the question, though he later amended that pessimism, erring towards the tie "probably" being beyond his side.
Real Madrid's to-qualify odds of 1/12 tell you all you need to know - Chelsea are 7/1 - and certainly Tuchel's defending champions are going to have to do something very few teams before them have managed if they are to take a place in the last four.
The other Tuesday night quarter-final between Bayern Munich and Villarreal is far more finely balanced after Unai Emery's men won the first leg 1-0 in Spain. But with Bayern 1/3 to qualify, a backlash from the Germans is envisaged.
Real Madrid are 29/20 to beat Chelsea again with the Premier League outfit a 7/4 chance. The draw is 5/2 and it was 1-1 between the sides when they met in the Spanish capital in last season's semi-final, which Chelsea went on to win 3-1 on aggregate.
That Chelsea did win by a two-goal margin in the second leg - albeit at Stamford Bridge - should offer a crumb of comfort.
And Real fans - if not their players - have seen their side stunned with ties at their mercy, though admittedly not very often.
Real have won their last nine Champions League quarter-finals, but their last losing last-eight showdown, came from nowhere in 2003-04 against Monaco, a team they beat 4-2 at home only to lose the away leg 3-1 with Fernando Morientes, on loan from the Bernabeu, doing the damage.
On the 36 occasions when Real have won the opening away leg in any Uefa competition, they went on to win the tie 34 times, most recently against Atalanta last season. They had lost on the previous occasion, however, against Ajax in the 2018-19 Champions League round of 16, winning 2-1 away then being humbled 4-1 at home.
And Chelsea fans of all vintages will tell you there is hope because they've seen their beloved side produce dashes of the unthinkable in the past.
Way back in 1971 they trailed Bruges 2-0 in a Cup Winners' Cup tie but they turned it around back in London, Peter Osgood sending the game to extra-time and an eventual 4-2 aggregate success.
A decade ago this week Chelsea bounced back from a 3-1 loss at Napoli winning 4-1 at home and going on to win the Champions League. Two years later and Demba Ba was the hero as the Blues recovered from another 3-1 first-leg loss, this time at Paris Saint-Germain, to produce an incredible comeback on a night their fans will never forget.
All of those games produced goals and lots of them and you sense there will be plenty in Madrid, if only because Chelsea have to take risks.
It's 8/13 that both teams score, 4/5 there are over 2.5 goals, something Chelsea managed with bells on at Southampton on Saturday with a welcome 6-0 romp as they bounced back from those heavy home defeats by Brentford and Real.
Since their goalless League Cup final loss to Liverpool, Chelsea have played nine times, winning seven of those and have scored 23 times. They have, however, conceded 11.
Real have won eight of their last nine, most recently a 2-0 success over Getafe which maintained their 12-point lead in the title race. Carlo Ancelotti fielded a strong side, including first-leg hat-trick hero Karim Benzema, who failed to find the net for the first time in eight games.
The other of Tuesday night's quarter-finals is on a knife-edge after Bayern Munich were pipped 1-0 at Villarreal, a result which saw the German six-time champions eased to 9/2 to go on and lift the cup and the Spaniards cut to 40/1. That's the same price as Chelsea.
Bayern are a seriously short 2/9 for victory to take care of Emery's challengers, who can be backed at 19/2 to prevail at the Allianz Arena.
Bayern are in the better form of the two sides, Villarreal having failed to win any of their last three in La Liga, arguably being distracted by the magnitude of this tie. It's a run of form which has all but ended any hope of returning to Europe next season via their league position.
Bayern, in contrast, are unbeaten in the league for over two months and nine points clear of Dortmund in their quest for a 10th successive Bundesliga crown.
Bayern have experience on their side - this is their 10th visit to the last eight in the past 11 campaigns whereas it's the first time Villarreal have made it this far in 13 years.
And the Germans are also blessed to have Robert Lewandowski, 15/8 to open the scoring and 1/3 to notch at any time.
The Pole has bagged 12 in the competition to date, including braces against Barcelona and Dinamo Kiev and hat-tricks against Benfica and Salzburg. Stop Lewandowski and Villarreal will think they have a chance of upsetting the odds.