Once more, the necessity to pick up points outweighed pride as Villarreal took all three points against a Leganés side that put up a fight but ultimately came away with nothing.
Calleja's men continued their revival and moved four points away from the relegation zone, leaving Girona and Levante in even more trouble as they battle with Real Valladolid to stay in the first division. Further back, Rayo and Huesca look like they might already be too far gone in the battle for safety.
Villarreal's greater desire to win the game was on display from the outset, as they started quickly and even took the lead through a Samu strike that was duly ruled out by VAR before five minutes had even passed.
Villarreal looked dangerous almost every time they reached the opponent's penalty area, and Leganés needed goalkeeper Iván Cuéllar to keep out an effort from Toko Ekambi as Samu continued to cause the defence problems. Leganés, meanwhile, looked toothless going forward and failed to create any real chances in the first half.
After the break, the neves of the home crowd were only eased when Bacca put the 'Yellow Submarine' ahead as he tapped home the rebound after Cuéllar saved well from a Toko Ekambi header.
The goal seemed to take the weight off of Villarreal's shoulders and, led by Santi Cazorla, they put breathing-space between themselves and the visitors as Toko Ekambi placed a fierce shot out of the reach of the diving goalkeeper.
Leganés forced a nail-biting last 5 minutes as Álvaro fouled Braithwaite to give the away side a penalty, which was gratefully tucked home by Nabil el Zhar.
Villarreal responded well, however, and saw the game out to gain three vital points in their quest for suvival.