From Longman Dictionary of Contemporary Englishthe man of the moment/hour/yearthe man of the moment/hour/yeara man who has recently done something important Olson was the man of the hour when the team beat the Tigers. → man
Examples from the Corpus
the man of the moment/hour/year• Back in 1831 the man of the moment was one Squire George Osbaldeston.• You ought to be the man of the hour.• That's what makes Bush the man of the hour, for these are indisputably good times.• Except for one player, the man of the moment in the Kingdome.• Sean Bean's the man of the moment.• Miltiades was the man of the hour, and his advice was to strike at once and win back the Cyclades. 