Silica bers have been successful used to deliver high-power high-energy laser beam in the near-infrared and visible range but suffer from high absorption and color formation in the UV spectrum which disqualify then for such wavelength. Recently, the advances of inhibited-coupling hollow-core photonic crystal bers made them as an unique tool to transport UV radiation thanks to an ultralow overlap with the silica cladding and record losses down to 10 dB/km. By further optimizing such ber, we report in this letter a record single-mode delivery of 23.3 W (155 μJ) with 92% transmission from a 343 nm, 10 ns, 150 kHz laser source, corresponding to an improvement of the current state-of-the-art by two orders of magnitude.