Confident Tiafoe 'flying high' after Japan Open start

he dispatched Japanese wild card Uchiyama with little fuss.

Well, yeah. Uchiyama is ranked 314th in the world (compared to Tiafoe at 19). As most tournaments do with their home country's players, the Japan Open gave all its wild card entries to Japanese players, regardless of how lowly ranked they are. They're all being dispatched rather easily in the first round vs. the quality opponents from overseas who actually qualified for the tournament due to their own successes.