They’ve played 45 matches each this season but still very little divides Wales two top football teams - in fact it’s just three points.
They say the Championship is one of the toughest leagues in the world and promotion to the Premier League is even tougher.
Both Cardiff and Swansea have had topsy-turvy seasons, and pre-lockdown it was looking unlikely that either side would finish in the top six and a play-off position.
But the resumption of the league after a three month break seemed to rejuvenate both sides, and we're now in a situation where the final match of the season will decide the fate for the south Wales teams.
What’s the situation at the top?
Leeds United became the first side to win automatic promotion.
West Brom and Brentford can still secure automatic promotion on the final day of the season, whilst Fulham are also still in the running.
Two of those teams will miss out on the automatics and enter the play-offs, where they will be joined by two of either Nottingham Forest, Cardiff City or Swansea City.
So how could Wales' top two secure a place in the play-offs?
Cardiff City’s task is pretty simple. They will secure a top six position if they draw or win against bottom of the table Hull at home.
Swansea’s route isn’t as simple. They are away to fifteenth placed Reading and they must win and hope Cardiff slip up and lose to Hull.
Both teams secured a win on Saturday, with Cardiff beating Middlesbrough 3-1 and Swansea scraping a 1-0 win over Bristol.
But even if Cardiff do win, there is another way Swansea could make it into the play-offs - and this is where things get complicated!
If Nottingham Forest in fifth place lose, it could all go down to goal difference.
Swansea would need a win and a six-goal swing in terms of goal difference (Forest are on +11, Swansea are on +6) to guarantee a play-off place.
This result would also mean that both Welsh clubs would make the play-offs - a scenario both neutrals and Welsh journalists are hoping for!
Cardiff City face Hull City at home while Swansea City play Reading away, with both games kicking off at 7.30pm on Wednesday 22 July.