  We characterize control of a qutrit implemented in the lowest three energy
levels of a capacitively-shunted flux-biased superconducting circuit.
Randomized benchmarking over the qutrit Clifford group yields an average
fidelity of 98.89 $\pm$ 0.05%. For a selected subset of the Clifford group, we
perform quantum process tomography and observe the behaviour of repeated gate
sequences. Each qutrit gate is generated using only two-state rotations via a
method applicable to any unitary. We find that errors are due to decoherence
primarily and have a significant contribution from level shifts. This work
demonstrates high-fidelity qutrit control and outlines avenues for future work
on optimal control of superconducting qudits.
