Borussia Dortmund survived its own defensive mistakes with four second half goals to collect a 4-2 triumph over FSV Mainz that lifted them level in the standings with the visitors and gave them a bit of breathing space in the Bundesliga relegation sweepstakes.
Mainz, which had surrendered six leads this season, the most of any side, did it again after a whirlwind start and is level on 22 points with Dortmund but retains 13th place on goal difference. Both are now four points clear of the bottom pair, SC Freiburg and VfB Stuttgart. That's hardly safe, but it was a welcome second straight league win for Dortmund, which had completed the first half of the campaign sitting bottom of the table.
Marco Reus, whose decision to stay with Dortmund by extending his contract was welcomed by the fans, delivered a goal and a fine assist while Neven Subotic, Pierre-Emerick Aubameyang and Nuri Sahin also scored for BvB.
Mainz swept into their lead just 54 seconds after the kickoff, Elkin Soto accepting the 18-yard chance to hit an empty net after Roman Weidenfeller was caught in no man's land and Subotic's attempted clearance only went as far as the Colombian on the left edge of the box. He lobbed it over the stranded keeper.
It was the kind of mess at the back which has characterized Dortmund's remarkably ineffective defense and immediately had Juergen Klopp trailing against his former club. It was not until the second half that the former Mainz boss could finally smile, but it was not for lack of effort from his current side in the opening 45 minutes.
Dortmund tried to reply to the Mainz goal immediately but Reus hit the right upright in the third minute, then Aubameyang brought the best from keeper Stefanos Kapino in the eight minute. Kapino was playing because regular Loris Karius received a red card a week ago so served a suspension. Aubameyang broke away in the 30th minute and went down under a 50-50 challenge from Pierre Bengtsson but referee Tobias Stieler waved play-on and when Dortmund attacked again a minute later Reus blazed a wide-open chance well over the bar.
Shinji Kagawa also had a decent look in the 43rd minute but sliced his drive past the near right post. That profligacy in front of goal meant that Mainz held onto to the lead at the interval despite having taken just that one shot.
Dortmund's shooting luck changed after the interval, which began wildly with three goals in the first 11 minutes.
The Dortmund equalizer finally arrived in four minutes when Subotic rose on the near post side to a Marcel Schmelzer corner and delivered a powerful, 14-yard header that beat Kapino cleanly. Kagawa had won the corner when his attacking cross was cleared at the last moment by Niko Bungert. Subotic got the better of Bengtsson in the air on the resulting corner.
Five minutes later, Reus put Dortmund on top 2-1 when he accepted a sweet Kevin Kampl through pass down the inside right channel, rounded Kapino and slotted home. Ilkay Guendogan had started things by finding Kampl in space at the top of the area.
That Dortmund lead lasted just two minutes, however, when referee Stieler played a correct advantage after Shinji Okazaki was fouled while leading an attack. The ball broke free to Yunus Malli, who turned past one defender and picked the near top right corner from 16 yards.
After that flurry, Dortmund's imprecision temporarily returned and Klopp sent on Henrykh Mkhitaryan for Kampl with 20 minutes left to seek some inspiration.
That brought an immediate reward although it was the quicksilver Reus producing the wonderful pass that sprung Aubameyang to put the home team back on top. Reus turned inside on the left flank befrore hitting a right-foot pass that found Aubameyang behind the defense to cooly slide the ball past Kapino.
Sahin was on the spot to snap home the fourth in the 78th minute when Aubameyang's powerful free kick could only be parried by Kapino at his right-hand post. The ball fell into Sahin's path and he made no mistake, the goal touching off the kinds of celebrations in the Signal-Iduna-Park which have been all too rare this campaign.
Saturday's six-match program features; Bayer Leverkusen vs. VfL Wolfsburg; Bayern Munich vs. Hamburger SV; Borussia Moenchengladbach vs. Cologne; Hoffenheim vs. VfB Stuttgart; Werder Bremen vs. Augsburg; and Eintracht Frankfurt vs. Schalke 04.
