Cristiano Ronaldo's hopes of lifting his first silverware since moving to Al Nassr in Saudi Arabia were dented on Friday after they were beaten 2-1 at home by Al Qadsiah.
Ronaldo, 38, opened the scoring in the 32nd minute, reacting fastest to some suspect goalkeeping and slamming home from close range.
However, that lead did not last long. Julián Quiñones levelled the affair just five minutes later, chesting down a looping cross from the left byline before finishing adeptly.
Quiñones then turned provider in the second half after Al Nassr failed to convert a considerable possession advantage into meaningful chances.
The Colombia-born Mexico international acrobatically controlled a cross at the far post and directed it back across goal with his first touch to where former Arsenal and Borussia Dortmund star Pierre-Emerick Aubameyang waited unmarked to give the visitors the lead.
Ronaldo and his teammates worked hard to force an equaliser but were unable to breach Koen Casteels' net and fell to a defeat that could have serious implications for their league-title challenge.
Stefano Pioli's team remain third in the Saudi Pro League but are six points behind leaders and reigning champions Al Hilal having played a game more.
Al Qadsiah move fifth with the win, level on points with Al Nassr and Al Shabab.
