After nearly two decades of design, construction and commissioning, the CMS detector was operated with colliding LHC proton beams for the first time in November 2009. Collision data were recorded at centre-of-mass energies of 0.9 and 2.36 TeV, and analyzed with a fast turn-around time by the CMS collaboration. In this talk I will present a selection of commissioning results and striking first physics resonances observed. Then I will discuss the analysis of the transverse momentum and rapidity distribution of charged hadrons, which led to the first CMS physics publication. The excellent performance of the CMS detector and agreement with predictions from simulation are impressive for a collider detector at startup and show a great potential for discovery physics in the upcoming LHC run.