The French side took an early lead through Baptiste Santamaria’s stunning long-range strike. However, West Ham fought back and managed to level the game in the second half when Tomáš Souček scored a towering header from a free-kick.
Despite the Hammers’ efforts, Rennes regained the lead 15 minutes before the final whistle, with France U21 international Arnaud Kalimuendo flicking home from close range.
In their quest for another equalizer, West Ham pushed valiantly, but in the end, Angelo Ogbonna’s unfortunate own goal sealed the victory for the hosts in north-western France.