Gojko Kacar's 87th-minute winner gave Hamburg a huge boost in their bid to avoid relegation, securing a 2-1 triumph at Mainz on Sunday.
Bruno Labbadia's men have spent much of the season in the bottom three, but Sunday's victory - their second in a row - lifted the six-time Bundesliga champions up to 14th.
The match was marred, however, by a 33rd-minute injury to Mainz's Elkin Soto, who reportedly suffered a complete dislocation of his knee in a collision with Rafael van der Vaart.
Mainz general manager Christian Heidel responded to the news by revealing that the Colombian - who joined in January 2007 - will be offered an immediate contract extension as a result, with his current deal expiring in June.
The mental state of Mainz was seemingly affected by the injury and Hamburg took the lead just four minutes after play resumed, Julian Baumgartlinger deflecting Heiko Westermann's cross into his own net.
Although Yunus Malli – Soto's replacement – restored parity 14 minutes from time, Kacar fired in from 18 yards right late on to clinch a potentially vital away win for Hamburg, with Daniel Brosinski's subsequent red card rounding off a miserable day for the hosts.
In the day's late kick-off, Lucien Favre claimed his 100th win as a Bundesliga coach with a late 2-1 triumph at his former club Hertha Berlin, moving Borussia Monchengladbach to within two points of second-placed Wolfsburg.
Valentin Stocker cancelled out Max Kruse's 11th-minute opener for Gladbach with a swift equaliser and the two sides looked destined to finish all-square.
Yet Ibrahima Traore proved decisive five minutes from time, cutting in from the right and curling an unstoppable left-footed effort beyond Thomas Kraft, restoring Gladbach's two-point lead over Bayer Leverkusen, who beat Bayern Munich 2-0 on Saturday.
