Heading into their Champions League last 16 first leg against Zenit St Petersburg, Benfica boss Jorge Jesus would have been forgiven for feeling confident that his league leaders could steamroll the Russian Champions with something to spare and reach the quarter-finals in comfortable fashion for the first time since 2006.
In reality, while Zenit held their own, snatching a late winner through Roman Shirokov in an enthralling 3-2 win, the plaudits went the way of Benfica, who with two away goals went into the return leg as firm favourites.
However, what Jesus can not have expected, was what the result would to his side's league form. Their five point gap at the top has been erased, and replaced by a three-point deficit from FC Porto, O Classico victors last weekend.
Jesus doesn't just have defeat to contend with following the Porto showdown, with Ezequiel Garay out of the Zenit return with a knee problem, and Pablo Aimar more crucially missing through suspension.
Such are their problems, it will require another inspired showing from Nicolas Gaitan to secure the club's passage to the last eight, where they stand every chance of playing the role of dark horse.
Among a team of hard working, crafty individuals, Gaitan is the stand out talent. His five assists in the group stage were the cornerstone to helping knock-out Manchester United and finishing top of Group C ahead of Basel. His impressive performances have been such that United and neighbours Manchester City have made their interest known.
Benfica appear consigned to losing him, but until then will demand a commanding showing from their talisman. His link up with Oscar Cardozo, who already has four goals in the Champions League this season, will be crucial.
Zenit are likely to play into Gaitan's hands, having proved an ability to concede goals with seven goals in as many games in this season's main draw. The Russians are likely to attack from the off, sink a killer away goal and go back into their shell. The opening goal is likely to dictate who will go into the quarter-final draw.
Hence, the patience of Gaitan will be crucial. City and United are likely to be watching closely at the temperament of the 24-year-old in arguably the biggest game of his career. Another glowing showing, and it won't just be the Premier League the pair will be fighting over in the coming months.