Group E of the 2018 World Cup kicks off on Sunday with a clash between Costa Rica and Serbia at the Samara Arena, in what promises to be an intriguing clash.
Brazil are the outright favourites to top the group but second place is up for grabs and both sides will be hoping that they can slip through into the last 16.
Costa Rica reached their second successive World Cup after finishing second in the CONCACAF qualifying round. They were defeated just twice in 10 matches and only conceded eight goals - the second best defensive record behind group winners Mexico.
Serbia qualified for the first time as an independent nation after pipping both Ireland and Wales to top spot in Group D of European qualifying. They finally started to demonstrate some of their potential as an international force, scoring 20 times and losing just once along the way.
Newcastle striker Alexander Mitrovic, who was on loan at Fulham for the second half of the 2017/18 season, was a standout performer. scoring six times during qualification.
Sunday's clash will mark the first even encounter between the two countries.
Serbia are managed by Mladen Krstajic, a young coach who ended his playing career is 2011 after playing for the likes of Bundesliga sides Werder Bremen and Schalke.
The 44-year old took charge of Serbia permanently in January after acting as the interim manager since November last year. The former centre-back has never taken on a role as a head coach before now, only having experience as an assistant for both the national side and as a sporting director for Partizan Belgrade.
He has experience of featuring at a World Cup as a player though, with Krstajic taking part at the 2006 World Cup in Germany for Serbia and Montenegro.
Oscar Ramirez is the man in the opposite dugout and he has been the Costa Rica manager since 2015, after succeeding former Premier League striker Paulo Wanchope. He was Wanchope's assistant but after the former West Ham star got involved in a scuffle during a match against Panama, Ramirez took over.
He was also a former player and represented his national side 75 times between 1985 and 1997, scoring 6 times.
Last Six Matches:
Costa Rica: LLWLWL
Costa Rica's World Cup preparations have been far from ideal and they have now lost four of their last six matches in the run up to the tournament. Most recently they faced up to two of group G's big hitters, England and Belgium. They were defeated 2-0 against England and 4-1 against Belgium.
Costa Rica built their previous World Cup campaign on being able to effectively keep the ball out of the net and in their last two victories, they have been able to keep a clean sheet. The worry for them will be whether they are able to be just as successful at the other end of the pitch.
Serbia's form has been inconsistent but when they are good, they are very good. They faced up against two South American sides in an attempt to get a better understanding of their prospective group D opponents Brazil and potentially Costa Rica.
They were defeated 1-0 by Chile, before demolishing Bolivia 5-1 days later - Mitrovic scoring a hat-trick. This result will have been a huge confident boost for Serbia and they will be hoping that they can continue this goalscoring form in Sunday.
Costa Rica have no reported injuries but after being defeated comfortably in both of their warmup matches, there will be plenty of questions as to who will be in the starting XI on Sunday. No-one really cemented a position, particularly on the flanks. Joel Campbell, Bryan Ruiz, Christian Bolanos and Johan Venegas will compete for two spots, with each player full of individual quality.
Serbia similarly have a full contingent to choose from and given how excellent they were against Bolivia in their final warm-up match, it would be a surprise to see any changes in the starting lineup. Star man Sergej Milinkovic-Savic will be expected to play in a deeper role alongside Manchester United midfielder Nemanja Matic.
Costa Rica (5-4-1): Navas, Oviedo, Duarte, Acosta, Gonzalez, Gamboa, Campbell, Guzman, Borges, Ruiz, Urena
Serbia (4-2-3-1): Stojkovic, Kolarov, Tosic, Milenkovic, Ivanovic, Matic, Milinkovic-Savic, Kostic, Ljajic, Tadic, Mitrovic
Both sides will be pleased that they are avoiding Brazil in their opening match and as such will be eager to get some points on the board.
Costa Rica can defend astutely and with a keeper of Keylor Navas' quality in goal, they always have a chance of keeping a clean sheet. Their issue will be in in front of goal and they will be coming up against a vastly experienced and solid Serbia defence.
Serbia will be looking to exercise the ghosts of their last tournament appearance where they crashed out in the group stages in 2006 and this side is certainly capable of doing some damage to a number of teams this summer.
With Milinkovic-Savic pulling the strings from the heart of midfield and Alexander Mitrovic in red-hot form, Serbia should be too much for Costa Rica to handle.
Prediction: Serbia 3-0 Costa Rica