Previously I would have said yes, but after what happened to Bergmann a few games back, I'm not sure I fully understand the rules for wins and losses, so I'm going to have to defer to anyone else who might know.
Off the top of my head, the starting pitcher has to pitch 5 innings minimum, but his team cannot be tied or give up the lead. Bacsik left in the 6th and the game was at least tied. Rivera was the pitcher when the Nationals took the lead in the bottom of the 6th, and is still in line to be the winning pitcher. As I understand how it works from reading the rule re Bergmann's game a while back.
Saul Rivera