Ten-man Borussia Monchengladbach suffered a 1-0 defeat at SC Freiburg after substitute Nils Petersen's superb second-half header dented their Champions league qualifying hopes in a lively Bundesliga game on Friday.
The result left Gladbach, who had Alassane Plea sent off after 68 minutes, fourth on 56 points from 30 games, with fifth-placed Bayer Leverkusen level on points with them ahead of Saturday's home game against leaders Bayern Munich.
With Gladbach piling on more pressure after the break, Petersen met Vincenzo Grifo's cross 67 seconds after coming on and headed past Sommer from 10 metres against the run of play in the 58th minute.
Freiburg gained the upper hand after Plea was dismissed 10 minutes later for a second bookable foul and Sommer again denied Hoeler with a fine reflex save in the dying minutes.
The visitors threw men forward late on and whipped a flurry of crosses into the penalty area but the Freiburg defence, superbly marshalled by Schwolow, held out comfortably.
Freiburg, who are chasing a Europa League qualifying spot, stayed eighth on 41 points but are within a point of the two sides above them ahead of the last four rounds of games.