In the heat of the 2016 U.S. presidential election, a certain candidate promised his supporters that they would be "tired of winning."

It's a sentiment that could just as easily apply to observers of the Samurai Blue after their fifth shaky one-goal win of the Asian Cup, this time against Southeast Asian champions Vietnam in Thursday's quarterfinal match.

To be fair, a few missing pieces from last Monday's narrow 1-0 round-of-16 win against Saudi Arabia fell into place. But will the rest of the puzzle be solved in time for Monday's semifinal matchup against Asia's No. 1-ranked Iran?