Jake Hesketh and MK Dons celebrated promotion from League Two as they beat Mansfield Town to pip the visitors to the last automatic spot.
The two teams were level on points heading into the winner takes all contest, with Mansfield holding a superior goal difference.
But after just two minutes, David Wheeler headed home Dean Lewington’s inswinging corner and they held on to earn a 1-0 success and a first clean sheet since March.
In Spain, Sofiane Boufal played 71 minutes as Celta Vigo stunned La Liga champions Barcelona. Maxi Gomez opened the scoring in the 67th minute, before former Liverpool man Iago Aspas converted a penalty that was awarded by VAR.
Elsewhere, Guido Carrillo also enjoyed success as Leganes recorded a 3-0 victory at Sevilla. The Saints forward came off the bench to replace goalscorer Youssef En-Nesyri on 86 minutes, as Martin Braithwaite and Oscar got the other goals.