Real Sociedad defeated Benfica 1-0 on Tuesday in Lisbon, becoming the third group in the Champions League to upset the Portuguese champion without a goal from Brais Méndez. The midfielder was set up by Ander Barrenetxea to score the game-winning goal in the 63rd minute. The Spanish visitors scored a goal that they deserved because they controlled the game throughout Group D. Méndez scored in the previous group games' 1-1 draw with Inter Milan and 2-0 triumph against Salzburg.

Although they missed multiple opportunities, the visitors placed Benfica under pressure. In the first half, both teams had goals disallowed for offside. At the start of the second half, Benfica coach Roger Schmidt introduced replacements Arthur Cabral and Orkun Kokçu in an effort to resurrect his offensive. Benfica is unlikely to go past the group stage after the Portuguese champion team lost three in a row and failed to score a goal in each of those games.