Vitoria Guimaraes knocked Benfica out of the Portuguese Cup in the fourth round with a 1-0 away win thanks to a first-half goal by defender Gustavo Lazzaretti.
The Guimaraes player rose above the Benfica defenders to head in from a corner by Desmarets in the 25th minute.
Benfica, currently top of the Portuguese Premier League, suffered their first home defeat since coach Jorge Jesus took charge in the summer.
Earlier on Sunday, Sporting progressed to the fifth round by beating third division side Pescadores 4-1 away with goals from Miguel Veloso, Joao Moutinho and Liedson.
Porto's fourth round away match against second division side Oliveirense on Saturday was postponed after the referee deemed the pitch did not meet the required conditions.
