The opportunity left on the table was the Turner 2 out single when Hale sent Suzuki
Arguably, it was the failure in the first inning to get Turner home from third with one out. I hate to fall back on clichés like "setting the tone", etc., and one of things about baseball is it lets us second guess numerous individual decisions from pitch selection on, and argue till we are blue in the face. One can wonder, however, how, the game might have progressed if Sanchez was staked with an early lead. Some pitchers like Scherzer can give up an early lead and not really change their game plan too much, but others can come to mound wondering if it is all on them and the offense might not be there today. They start nibbling and find themselves behind in counts, and then are forced to make risky pitching choices, and the results leave the park or bounce off the Green Monster. I honestly don't know enough about Sanchez to know if he falls into that category.
Anyway, plenty of missed opportunities in multiple innings.