  We present the first kinematical detection of embedded protoplanets within a
protoplanetary disk. Using archival ALMA observations of HD 163296, we
demonstrate a new technique to measure the rotation curves of CO isotopologue
emission to sub-percent precision relative to the Keplerian rotation. These
rotation curves betray substantial deviations caused by local perturbations in
the radial pressure gradient, likely driven by gaps carved in the gas surface
density by Jupiter-mass planets. Comparison with hydrodynamic simulations shows
excellent agreement with the gas rotation profile when the disk surface density
is perturbed by two Jupiter mass planets at 83 au and 137 au. As the rotation
of the gas is dependent on the pressure of the total gas component, this method
provides a unique probe of the gas surface density profile without incurring
significant uncertainties due to gas-to-dust ratios or local chemical
abundances which plague other methods. Future analyses combining both methods
promise to provide the most accurate and robust measures of embedded planetary
mass. Furthermore, this method provides a unique opportunity to explore
wide-separation planets beyond the mm continuum edge and to trace the gas
pressure profile essential in modelling grain evolution in disks.
