In a super-powered showdown, Jiren easily defeats Broly, proving that he is the stronger fighter. Jiren's quick and decisive victory over Broly highlights his ability to shut down his opponent's power growth.

Broly and Jiren are the two strongest opponents Goku has ever fought, likely stronger than Beerus himself judging by the God of Destruction's obvious discomfort watching Jiren fight. However, with a lifetime of rigorous training and nigh unflappable combat discipline, Jiren has a definitive edge against the more raw, uncontrollable Broly.

If we assume Jiren has stayed at the same power level as last time, it is unlikely that he could have become stronger than Broly. Besides his natural strength, Broly has been training to control his Legendary Super Saiyan form better. If he manages to remain in control, he could become a nigh-unbeatable adversary.