Fuenlabrada bounced back from last week's heavy defeat at EWE Baskets in Germany and won in the EuroChallenge at Bemaco SPU Nitra on Tuesday.
Scoring machine Kirk Penny had 22 points as the Spanish club claimed an 86-75 victory.
Fuenlabrada only led 46-43 at half-time in the Group A game but took control in the third quarter, which started with a Penny three-pointer.
The New Zealander followed with a jumper to make it 51-43.
The Spaniards went in front by 19 in the quarter before taking a 75-59 advantage into the last 10 minutes.
The Slovakian fans were starting to believe a great comeback might be on the cards when a Branislav Tomek free-throw closed the gap to 76-67.
Tomek had 18 points in the game.
Lubos Barton stopped Nitra cold in their tracks when drilling a shot from the arc, and veteran Fuenlabrada shooting guard Ferran Laviña followed with another three-pointer to make it 82-67.
The Madrid club coasted the rest of the way to their second victory.
Nitra slumped to a third straight defeat.
Robert Vaden's 20 points and seven rebounds led the home side.