Nicolai Muller and Adam Szalai both scored a goal and set up another as Mainz beat Cologne at home to pull further away from the Bundesliga relegation zone and keep the visitors in the bottom three.
Eugen Polanski made it 1-0 in the 19th minute from the spot for Mainz and Mohamed Zidan doubled the lead after 32 minutes. Muller pushed the margin to 3-0 in the 37th minute and Szalai scored goal number four in the 55th minute.
Mainz had won just once in their last four games but improved to 36 points - seven points ahead of Cologne, who are 16th with 29 points after five games without a win.
Mainz pulled ahead as Polanski converted a spot-kick into the upper right corner of the goal after Ammar Jemal took down Szalai in the area.
The hosts doubled the lead 13 minutes later as Muller laid on a chance from the left side to Zidan, who struck into the lower left corner. It was the Egypt international's seventh goal in 10 games since joining Mainz.
The lead was 3-0 with eight minutes of the half to go as Eric Maxim Choupo-Moting steered the ball into the path of Muller, who beat Cologne goalkeeper Michael Rensing.
Mainz finished off Cologne for good nine minutes after the break with Muller playing a ball to Elkin Soto for a cross to Szalai, who struck home from seven yards out to make it 4-0.
Cologne missed a chance to pull a goal back in the 68th minute as Lukas Podolski's long-range free-kick went just wide.