Mamer pulled off a surprise 1-0 away victory against league leaders Swift Hesperange in the Luxembourg National Division on March 8, 2026. This result at the Stade Alphonse Theis was a major upset that threw the title race wide open. The only goal of the game came against the run of play in the first half, as Mamer capitalized on a defensive error to score. Swift Hesperange piled on the pressure in search of an equalizer, hitting the woodwork twice, but Mamer's defense and goalkeeper stood firm to secure a historic win. The defeat was a significant blow to Hesperange's championship hopes, while Mamer celebrated a famous result in their fight for survival. The Mamer manager hailed it as a perfect defensive display, and the Hesperange coach expressed frustration at his team's profligacy.