Duda scored twice as Malaga came from behind after throwing away the lead to win 3-2 at home to Sevilla in the Primera Division.
The Portuguese playmaker opened the scoring in the first half and then grabbed the winner seven minutes from time to move Malaga clear of the relegation zone.
Sevilla looked to have turned the match around in the second half as goals from Carlos Bacca and Federico Fazio put them in front, but the game turned for a second time.
Samu made it 2-2 in the 77th minute before Duda had the final say as Sevilla's European hopes took a hit at the hands of their Andalusian rivals.
Rayo Vallecano avoided defeat for the first time in three league games by drawing 0-0 at Levante, but remained in deep trouble in the Primera Division relegation zone.
This was an evenly matched game at the Ciutat de Valencia stadium which saw few openings until a frantic final ten minutes, but neither team were able to take any of their chances.
Rayo are now four points from safety, but could see the gap between themselves and 17th-placed Elche widen to seven points should Fran Escriba's side beat Almeria on Sunday.
Levante dropped to ninth, level on points with local rivals Valencia.
Getafe were the width of a post away from earning a much-needed win against Real Valladolid but had to settle for the draw which hardly helps either side.
Six defeats and a draw in their last seven competitive matches had seen Getafe tumble down the Primera Division standings and crash out of the Copa del Rey, but that dismal winless run looked set to come to an end as Diego Castro's thunderous second-half stoppage-time strike arrowed towards the top corner.
However, the 25-yard effort crashed against the post and stayed out, and soon afterwards the full-time whistle went to leave Getafe and Valladolid - who had also struck the woodwork early on - still in trouble near the foot of the standings following a goalless draw.