Naby Keita scored twice as RB Leipzig tightened their grip on second place in the Bundesliga with a comfortable 4-0 victory over Darmstadt at the Red Bull Arena.
Keita opened and closed the scoring in Leipzig's routine win over the bottom side, who crumbled after having Sandro Sirigu sent off and conceded the last two goals in the space of 91 seconds.
Hoffenheim's 3-1 victory at Hertha Berlin on Friday had moved them to within a point of Ralph Hasenhuttl's men, but Keita put them on course to end a three-match winless run and restore their four-point cushion when he volleyed Emil Forsberg's deflected shot beyond Daniel Heuer Fernandes.
Fabian Holland wasted a glorious chance to pull Darmstadt level when he guided a shot wide in first-half stoppage time, and it proved costly after the restart.
Forsberg curled home his eighth goal of the season with a deflected finish from 20 yards, and things got even worse for Thorsten Frings' side.
Sirigu was given his marching orders after committing two bookable offences in the space of 10 minutes, and Leipzig made their extra man count.
Willi Orban glanced a header from Forsberg's corner into the back of the net in the 79th minute, and Keita completed the rout less than two minutes later.
Stefan Ilsanker caught Sidney Sam in possession and surged into the box before seeing his attempt to square parried to Keita by Heuer Fernandes, and the Guinea international slotted into an empty net.
Leipzig now hold a five-point advantage over fourth-placed Borussia Dortmund, who drew 1-1 at Schalke in the Revierderby, boosting their hopes of automatic Champions League qualification.