Actually he did much better. Kensei's bankai enhanced punch, just the backlash of which was enough to make a crater and level city blocks back against Wonderweiss, was caught by Mask. In turn Mask used 10x the force he did against Kensei against Renji and he caught his punch barehanded. Also it'd be cool but I don't think Rukia is stronger than Renji but she almost certainly got several times stronger and has a bankai now. Also the star beam is very potent. It blew a clean star shaped hole in Rose's torso. Much more potent than most attacks including Mask's punches. And potency truly matters. That's how sub block level wood chips from Juubito were life threatening to Naruto and straight up killed Neji.