Timo Werner struck twice as Monaco self-destructed in the Champions League on Tuesday, going down 4-1 at home to RB Leipzig to be dumped out of Europe early.
A woeful start from the hosts - winless in five Group G games - saw two Jemerson mistakes hand Leipzig a massive advantage in the first 10 minutes at Stade Louis II.
The defender first turned a low cross from Marcel Sabitzer into his own goal before gifting Kevin Kampl possession with a loose pass, the midfielder setting up Werner for the second.
Monaco were not finished causing problems for themselves, though, and Radamel Falcao fouled Willi Orban in the box to allow Werner to emphatically convert a 31st-minute penalty.
Although Falcao's header gave his side hope, that was soon extinguished by Naby Keita's fine goal on the stroke of half-time. Monaco are now guaranteed to finish bottom of Group G, meaning they will not play any further European football this term.
For Leipzig, a do-or-die clash at home to Besiktas - already confirmed as the winners of the group - awaits on matchday six, when Monaco visit second-placed Porto.
Leipzig knew a loss would send them out but they were gifted the lead just five minutes in.
Sabitzer burst clear down the right wing and tried to pick out Yussuf Poulsen with a low cross, only for Jemerson's interception to wrong foot helpless goalkeeper Danijel Subasic.
It was 2-0 to the visitors in the ninth minute, leaving Monaco with a mountain to climb. Jemerson was again at fault, the defender surrendering possession tamely to Kampl, who sent Werner through on goal to beat Subasic with a cute finish.
Keita Balde Diao forced a smart save from Peter Gulacsi and the goalkeeper had to be alert again to deny Falcao as the Ligue 1 champions rallied.
But more chaotic Monaco defending led to a third for Leipzig, Falcao clumsily bringing down Orban and Werner stepping up to crash home his 15th goal of the season for club and country.
It might have all been going to plan for Leipzig, but Sabitzer's dislocated shoulder forced his substitution and Monaco looked to have briefly given themselves a lifeline before the interval.
Gulacsi misjudged a Marcos Lopes free-kick, allowing Falcao to head into the gaping goal, yet Leipzig immediately restored their three-goal advantage with a clinical attack.
Marcel Halstenberg fed Keita outside the box, the Guinea international wriggling away from Kamil Glik and Fabinho to roll home a composed finish.
Gulacsi denied Andrea Raggi as the defender tried to turn in a free-kick after 58 minutes, but Leipzig were never likely to let a first away win in Europe slip, the Bundesliga side content to run the clock down.
Monaco - second behind Paris Saint-Germain in Ligue 1 - are well-placed to return to the Champions League next season, but an exodus of star names since their surprise run to the semi-finals last season has proved costly for Leonardo Jardim's side.