Having gone ahead through a Deivid own goal, the odds on Chelsea throwing away their lead against Fenerbahce in the second half must have been huge.
However, the roller coaster ride that is the Champions League threw up another surprise, when most of the other quarter-final results had gone according to plan.
Fenerbahce's Brazilian coach, Zico, had said before the game that his side would attack Chelsea - and that they did, albeit after a period of sustained pressure from Avram Grant's men. With both of Fener's full-backs playing in an advanced position, Zico may rein in his attacking intent for the second leg, as both Joe Cole and Florent Malouda were allowed far too much space in the first half. Now that Zico has struck the blow, he can afford to be cautious.
Indeed it was a substitute masterstroke that set things up. With all the focus on playmaker Alex, Colin Kazim-Richards' introduction early in the second half proved to be the real catalyst for the Turkish side and the former Sheffield United striker did well to take his goal. After an ill-fated spell in England, 'The Coca-Cola Kid' seems to have found his feet in the Turkish league and his pace and dynamism, alongside a lethargic looking Mateja Kezman, provided the Turks with a much-needed boost.
Still, although they were hit by a hammer blow from Deivid, Chelsea can be confident that they will create enough chances to get back into the game at Stamford Bridge. From the Blues' perspective, and given their immense home record, Avram Grant shouldn't have too many sleepless nights about the return leg next week.
More worryingly for Grant was the reaction of Frank Lampard to being substituted with 15 minutes left to go. Throwing a tantrum on the bench is the worst kind of publicity for the club, who are keen to tie the midfielder down to a new deal. The gossip columns will now be full of speculation over Frank's future.
One thing is for certain though. The away end at the Bridge next week will be packed to rafters with noisy Turkish supporters, as Fener have given themselves every chance of causing an upset.
Indeed, if Arsenal are to progress from their meeting with Liverpool, they'll have to cause an upset of their own at Anfield.
Dirk Kuyt's away goal at the Emirates last night may prove to be the difference and Arsene Wenger has done himself no favours by moaning about the manner of the draw.
Arsenal fans are well-versed in seeing their team dominate possession, without being able to make the crucial breakthrough. While headed goals are less of a rarity in North London with the aerial prowess of Emmanuel Adebayor nowadays, the 'beautiful football' that Wenger's youngsters play still comes up short occasionally.
That said, credit must be given to the stoic Liverpool defence. Deploying Jamie Carragher at right-back again, Benitez opted to use Hyypia and Skrtel, who have struck up a good understanding together in recent times and they were able to hold off Arsenal's attacking intent.
While Liverpool may have ridden their luck by escaping a penalty shout on Alex Hleb, they'll go into the second leg in confident mood - although have the small matter of a League meeting with the Gunners back at the Emirates on Saturday to contend with first.
Arsenal are more than capable of getting something at Anfield, but Liverpool's European pedigree suggests that the Reds will make it tough for Wenger's men. Benitez only has one target left for the season, and is unlikely to let it go easily.
Arsenal would do well to watch Manchester United's demolition of Roma on Tuesday night if they need any pointers in how to win away from home. Ferguson's men were totally dominant and, with an impressive recent record over the Italian title-chasers, had every reason to approach the match with confidence.
With Cristiano Ronaldo and Wayne Rooney in fine form and a defence that has only conceded 15 goals in the Premier League this season, United showed why they are one of the favourites for the Champions League this season with a commanding 2-0 win in Rome.
There really is no stopping Ronaldo at the moment and he proved the range of his abilities by heading a wonderful goal to set up the win. 'Arrogant and spiteful' he may be according to Roma's David Pizarro, but the Italians had no answer to his tricks without the influential Francesco Totti.
United, for their part, looked every inch a team in form and their only slight worry is over the fitness of Nemanja Vidic, who fell awkwardly and will be out for three weeks with a knee injury. Otherwise, a semi-final with Barcelona seems an inevitability.
Barca themselves showed their class in a first-half that looked more like a training exercise than a Champions League quarter-final, against Schalke 04. With one of the youngest and most talented strikers in Europe, Bojan Krkic, netting an important away goal, even the inconsistent Catalans will fancy their chances at the Nou Camp.
Though Schalke rallied in the second half and Barca failed to make any kind of impression on the game thereafter, a home game against one of the best teams in Europe seems like too tough a test for the Germans.
Still, as Fenerbahce upset the odds against Chelsea, so the stage is set for someone else to continue the intrigue of the Champions League. Next week will provide the finale to some cracking games, although the prospect of a Manchester United v Barcelona semi-final is something that can't fail to set pulses racing, wherever your allegiance lies.