Berlin - Hoffenheim missed out on an opportunity to move into the Bundesliga's top four on Sunday, suffering a heavy 5-1 home defeat by a Mainz side playing under newly appointed coach Achim Beierlorzer.
The hosts failed to win for the first time in five games as the visitors moved out of the relegation zone to 13th spot with only their third victory of the campaign.
Beierlorzer, who was sacked by struggling Cologne nine days before taking over at the Opel Arena on November 18, started his reign successfully despite Ridle Baku's first-half red card as Cameroon midfielder Pierre Kunde Malong scored twice to open his account for the season.
Levin Oeztunali claimed the first goal of proceedings on 33 minutes before his midfield partner Baku was dismissed seconds before the break for a studs-up challenge on the home side's Sebastian Rudy.
Mainz continued to attack in the second half, peppering the Hoffenheim box until an own goal from Pavel Kaderabek in the 52nd minute doubled their lead.
Kunde tapped in for his first of the season 10 minutes later before Andrej Kramaric claimed a consolation effort for the home side in the 83rd minute.
Jean-Paul Boetius snuffed out any chance of a comeback in the 90th minute, however, scoring on the break to make it 4-1 and Kunde added his second two minutes later to complete the rout.
Mainz coach Beierlorzer praised sacked former boss Sandro Schwarz, dedicating the victory to him.
"It was an amazing achievement," Beierlorzer said. "Sandro deserves a very, very large share of it. It's guaranteed that the team fought for him today and brought home the victory."
- Hertha woes continue -Earlier on Sunday, goalkeeper Rune Jarstein was sent off as Hertha Berlin continued to stutter, losing 4-0 at Augsburg.
Hertha lost a fifth straight game and slid below Augsburg after Philipp Max, Sergio Cordova, Andre Hahn and Florian Niederlechner scored for the hosts. Hertha are just a point above the relegation zone.
Left-back Max opened the scoring for the Bavarians in the 18th minute with a free-kick but the turning point came 10 minutes later.
Jarstein earned a red card with a studs-up challenge on Niederlechner. Cordova claimed the home side's second in the process.
Substitute Hahn added a third in the 52nd minute with a superb curling strike from the edge of the box. Niederlechner bagged his side's fourth in the 79th minute.
"The disappointment is understandably big, we have to digest that first," said Hertha captain Niklas Stark.
"There were so many things we did which you just can't do while playing away in the Bundesliga.
"We simply have to do better."
Earlier on Sunday, Borussia Dortmund's squad were booed and jeered when they appeared at the side's annual general meeting, with fans screaming "shame on you".
Coach Lucien Favre is under pressure as Dortmund, expected to challenge for the title after an ambitious close-season recruitment drive, languish in sixth after a draw to lowly Paderborn on Friday.
On Saturday, managerless Bayern Munich closed the gap at the top of the table to just a point with a 4-0 romp at Fortuna Duesseldorf as leaders Borussia Moenchengladbach suffered a shock 2-0 loss at Union Berlin.