Sport is full of unpredictability, which seems like an understatement on a day when the Golden State Warriors squandered a 31-point lead, at the Oracle Arena (home court) against the eighth seed, L.A. Clippers. Yet, this may be the week of sporting upsets with four closely fought Champions League Quarter Finals about to take place over Tuesday and Wednesday across Europe.

Here’s a look at the four games, and where it may be won and lost.

Barcelona vs Manchester United

Barcelona lead 1-0 after winning in Manchester, thanks to an own goal from Luke Shaw. 

Manchester United are returning to the scene of their most memorable triumph in the Champions League (They beat Bayern Munich of Germany in the final of the 1998-99 competition thanks to two late goals from Teddy Sheringham, and current head coach Ole Gunnar Solskjaer). The English club will feel confident having knocked out Paris St. Germain in the last round despite losing the first leg in Manchester. However, even the most fanatic United fan could admit that they were a little fortunate in victory.

Similarly, Barcelona haven’t looked all that comfortable despite their 5-1 win against Lyon in the last round. What was once considered to be the best midfield in Europe is starting to show more and more cracks. They are more reliant on their talisman Lionel Messi – 13 goals in his last nine appearances against English sides in the Champions League – who hasn’t really had the support of his teammates. The only player who has played at a high level this year apart from the Argentine, is the Spanish defender Gerard Pique. Long gone are the days when teams would fear the Barcelona midfield. Yes, they can still play keep ball, but they don’t have the same penetration as they once had.

I realise that most people will have ruled out United in this game, and I can understand why, but this Barcelona side can be beaten as long as Solskjaer’s team don’t lose their cool. Barcelona will likely try to use the 90,000+ fans packed into their famous Nou Camp stadium to put pressure on the match officials, and before you know it, Sergio Busquets (Barcelona Midfielder) will start throwing himself all over the ground in his usual heinous way. If the English club can avoid frustration, then they may just be able to upset the odds again, as unlikely as it may be.

Verdict: Barcelona 3 – Manchester United 2 (Barcelona go through 4-2 on aggregate)

Juventus vs Ajax

First leg was a 1-1 draw in Holland. 

Ajax are proving to be the dark horses of the competition this year. They dumped reigning champions Real Madrid out of the tournament with an amazing display of clinical finishing in the previous round. A similar display would have put them clear against Italian champions Juventus in this round. The side from Amsterdam were absolutely fantastic in the first game, but ended up missing chance after chance against a lacklustre Juventus before falling behind to a goal from none other than Cristiano Ronaldo.

These two teams are the complete antithesis of one another, which makes for an interesting match. Juventus have the experienced players, who have proven themselves to be amongst the world’s elite. On the other hand, Ajax will supply the youthful exuberance and in Frenkie De Jong, a player who is seen as the next big player to come out of the Ajax factory.

Verdict: Juventus 1 – Ajax 3 (Ajax go through 4-2 on aggregate)

Porto vs Liverpool

Liverpool lead the tie 2-0 thanks to goals from Naby Keita and Roberto Firminho).

I expect the second-leg in Lisbon to be end-to-end. Both teams definitely favour an attacking style of football, so expect plenty of goals. Although Porto possess some excellent players, well three of them to be precise (Jesus Corona, Octavia and Moussa Marega), they are no match for Liverpool.

Porto, in the last round against Roma, notched up a total of 23 shots (11 on target and 12 off), but ended up needing extra time to make it through. All throughout this year’s competition, they have tried to suffocate teams with their relentless attacking display at home, but Liverpool will be licking their lips at the prospect of seeing the huge spaces that will be left for the likes of Mane, Salah and Firminho to exploit. I expect the tie to be all but over by half-time with Porto coming out to salvage some pride in the second-half.

Verdict: Porto 2 – Liverpool 4 (Liverpool win 6-2 on aggregate)

Manchester City vs Tottenham

Tottenham surprised everyone by winning the first leg 1-0. 

Man City came into the tie as the favourite but were completely outworked in the first leg by a Tottenham side that didn’t stop forcing their will on the opposition throughout the entire 90 minutes. Yet, they only take a slender one-goal advantage into the second-leg which will be played in front of a packed Etihad Stadium. Tottenham will be without captain and top scorer Harry Kane, meaning that the likeable Heung-Min Son will prove the biggest threat to the home side.

Manchester City will definitely come into the game the more nervous out of the two teams as they attempt to achieve a historic quadruple by winning the English Premier League, League Cup, F.A. Cup and Champions League. The omens are not in favour of Pep Guardiola’s team, though. Man City have been eliminated by English clubs on all three occasions and have never managed to over-turn a first-leg defeat.

This is definitely going to be nail-biting tie in which the lack of an away goal for Manchester City will prove costly.

Verdict: Manchester City 2 – Tottenham 1 (Tottenham go through on the away goals rule)