Obr

[SAump]

OBR Balk, ball is live. If everyone advances at least one base, ignore the balk. That was not the case in the OP, I believe you did the right thing with NO pitch, runner(s) advance one base.

HTBT, and assuming concern for player safety,
A) Pop up to F1, R3 collides with F2 in front of plate over fair territory, warn runner who must slide or avoid contact with F2.
B) Pop up to F1, R3 collides with F2 in front of plate over foul territory, warn F2 not to obstruct the runner by blocking the basepath without the baseball.