They surpassed the previous record of 263-5, set by Royal Challengers Bangalore in 2013
Belgium threatened to overwhelm Switzerland when Thorgan Hazard scored twice in the first 17 minutes, the first from an awful mistake by Nico Elvedi in the second minute.
But the Swiss hit back to lead 3-2 at halftime with a penalty from Ricardo Rodriguez and a brace from Seferovic before Elvedi atoned for his mistake by heading them further in front in the 62nd minute and then Seferovic added a fifth.
The two sides finished level at the top of Group Two in League A -- the top tier -- with nine points and the Swiss qualified on having the better head-to-head record after Belgium's 2-1 win in Brussels.