The Champions League group stage is often written off as being a lucrative stroll for the big clubs against the smaller sides just making up the numbers.
While it is true that the seeding system favours Europe's traditional powerhouses at the expense of outfits with less history and money, there is still room for the odd surprise or two.
For example, last season both Manchester clubs, Porto and Borussia Dortmund all failed to make it through to the knockout phase, while APOEL Nicosia, CSKA Moscow and Basel all reached the last 16, with APOEL even reaching the quarterfinals.
Here are some of the more surprising things to have happened in this season's group stage, which will see its penultimate round of fixtures this week.
It is perhaps no surprise in itself that the champions of Germany are doing well in their group.
They returned to the Champions League group stage after a nine-year absence as Bundesliga winners last season, but finished bottom of their group.
Back again after retaining their domestic title, Jurgen Klopp's side have gone on a steep learning curve, currently topping a group which also includes Real Madrid, Ajax and Manchester City, despite selling star midfielder Shinji Kagawa in the summer.
However, even the most hardcore regular of the Westfalenstadion's Sudtribune could not have predicted their team would beat Real 2-1 in Germany and then secure a well-earned 2-2 at the Santiago Bernabeu.
With a potentially vital head-to-head advantage over the Spanish champions to go with their one-point lead at the top of the group—plus City's continued struggles in Europe—Dortmund look well set to put last season's failure firmly behind them.
Champions in Russia in three of the last five seasons, and having reached the knockout phase of the Champions League last term, Zenit looked set to mount a serious European campaign this time out.
Those prospects appeared to be further enhanced when, with the help of the huge financial backing of sponsors Gazprom, the club signed Brazil striker Hulk and Belgium midfielder Axel Witsel for fees of around €40 million each.
So far, that investment has garnered just one goal in the Champions League, and Zenit sit bottom of Group C having won just one and lost three of their games so far.
Hulk's last game in the competition—a fortunate 1-0 home win over Anderlecht on matchday three—featured a performance of almost comical ineptitude.
Their final two fixtures—a visit from group leaders Malaga and then a trip to AC Milan—do not augur well for Luciano Spalletti's team.
Despite losing one game each in their respective groups this season, Barcelona and Real Madrid both look on course to reach the latter stages without too much fuss.
So far, so predictable.
What is somewhat less of a banker is the performance of the other teams representing Spain each year.
Valencia—twice finalists at the turn of the century—have been frustratingly inconsistent in Europe ever since, but this season they are level on points with Group F leaders and last season's runners-up Bayern Munich.
But the bigger surprise was the fortunes of Malaga on their first season in the competition. Despite seeing huge investment in the playing staff over the past two years, financial troubles this term have led to the club having to sell a raft of its best players, while those who remain have not always been paid on time.
Despite that, the Andalucian club were the first to confirm their place in the last 16 after a 1-1 draw at AC Milan which saw them reach the significant 10-point mark with two games to spare.
When Celtic marked their 125th anniversary with a hard-fought 2-1 win over Barcelona at Parkhead, it was one of the greatest European nights in the club's history.
The Bhoys followed up their trip to the Nou Camp—in which they were unfortunate to lose due to Jordi Alba's late winner—with a win thanks to goals from Victor Wanyama and Tony Watt, a teenage striker who only made his debut for the club in the spring.
The Barca double-header was preceded by the Scottish champions claiming their first away win in the competition since 1986 with a 3-2 victory at Spartak Moscow.
Of course, all of this could mean nothing if they fail to earn points from their final two games—away at Benfica and at home to Spartak—and it is not unlike Celtic to let great results be rendered obsolete for failings elsewhere.
But few would begrudge Neil Lennon's side their place in the last 16 if they made it there, if only to provide the competition at least one more rousing atmosphere from the club's vocal faithful.