The second round of games in the Champions League group stage are complete and we're now starting to get a feel for how the teams are going to perform in this season's edition of the world's biggest club competition.
The usual suspects are performing well (the likes of Real Madrid, Barcelona, Paris Saint-Germain, Manchester United, Manchester City and Chelsea are all on maximum points) and the teams who were expected to struggle are doing exactly that (Qarabag, APOEL, Feyenoord, Olympiakos, Benfica and Anderlecht are all yet to register a point), but there are also some teams performing in a manner that would suggest they might cause a surprise going forward.
In this article, as top flight football temporarily pauses for an international break, we'll look at some of those teams who appear as though they could make a real impact in the 2017-18 Champions League campaign - perhaps they could even shock the world and win it!
Here are five potential outsiders for the Champions League this season...
Besiktas
We all remember the amusing "come to Besiktas" signing announcement videos during the pre-season transfer window this summer - and, as it turns out, those signings look to have turned the Turkish giants into a genuine European force.
Besiktas have won both of their Champions League group stage matches so far - defeating Porto 3-1 in Portugal and overcoming Leipzig 2-0 in Turkey - and they look like a very handy outfit. The other club in their group is Monaco, who look to be struggling in Europe this season after losing a plethora of last season's star turns, so you have to fancy Besiktas to breeze through to the first knockout round.
This summer's signings included the likes Gary Medel, Alvaro Negredo and Pepe - who, of course, has won the competition on multiple occasions - and they joined a team that already included former winner Adriano and Pepe's fellow Euro 2016 winner Ricardo Quaresma, so there's definitely a winning mentality at the club. A first ever European trophy certainly isn't out of their reach.
Napoli
Napoli are becoming Champions League regulars of late, with the Naples side currently competing in their fifth campaign in Europe's elite club competition since 2010 - and this time it really could be their year.
Although they narrowly lost their first game 2-1 in the Ukraine against Shakhtar, they got back on track in the second round of matches with a 3-1 home victory against Feyenoord. They've got Manchester City at the City of Manchester Stadium next, which obviously won't be easy, but they've got every chance of getting a result in England and could kick on from there.
It's Napoli's domestic form that is really catching the eye this season. They've won all of their first seven games, scoring an impressive 25 goals, and currently sit top of Serie A. If they can take that form into Europe, they'll beat anybody - and with a forward line that includes Dries Mertens, Lorenzo Insigne and Jose Callejon, the Partenopei will certainly never be short of a few goals.
Porto
Like Napoli, Porto have already lost a game in their Champions League group, having lost their opening game 3-1 against another of our potential outsiders - Turkey's Besiktas. However, their most recent match was an extremely impressive 3-0 victory against Monaco at the Stade Louis II.
As far an Porto's domestic season goes, they remain unbeaten eight games into the Liga NOS campaign, with the only blemish on an otherwise perfect record coming in Lisbon, in a highly respectable 0-0 away draw at fierce long-time rivals Sporting.
The Azuis e brancos have already proven capable of surprising the world in the Champions League in its modern format - they famously won the 2003-04 tournament under the stewardship of a certain Jose Mourinho - and with the experience of three-time winner Iker Casillas in the side, there's no reason why they can't pull off a shock like that for a second time.
Sevilla
In recent years, Sevilla have an incredibly impressive record in European competition. The Spanish side have won the Europa League/UEFA Cup five times since the turn of the millennium - and that's a great platform from which to bring that winning mentality to the Champions League.
Sevilla are currently top of their group, having held Premier League Liverpool to a 2-2 draw at Anfield, before comfortably overcoming Slovenia's Maribor 3-0 back in Spain.
It is, however, Sevilla's domestic form that is most impressive this season. They are second in La Liga, five points behind unbeaten leaders Barcelona, and two points - and three places - above current European champions Real Madrid. Wissam Ben Yedder is currently the Champions League's second-highest scorer - and with the likes of Steven N'Zonzi, Jesus Navas and Ever Banega in their team as well, there's certainly enough quality to potentially cause an upset.
Tottenham Hotspur
Tottenham have been underachieving for quite some time now, with the 2007-08 League Cup the only silverware they've won this side of the new millennium. There is, however, a genuine belief that something huge is on the horizon at the club - and that "huge" thing could very well occur in the Champions League this season.
Tottenham's strongest first choice eleven is as good as anyone's and they can undoubtedly beat any team on their day. They were drawn in the supposed "group of death" in this season's Champions League, but they've won both of their games so far - 3-1 at home to Dortmund and 3-0 in Cyprus against APOEL - and their upcoming double-header against Real Madrid will allow them to show they're capable of mixing it with the very best.
Harry Kane is the top scorer in the competition, with five goals in two games, and anything could happen if he keeps that form up. A lot will depend on whether or not Spurs can keep their squad fit, as they lack the depth of many other clubs. The Wembley factor could also play a big part - they're yet to win a home game in the Premier League this season - but Spurs will be hoping their success against Dortmund is a sign of things to come.
