Think everyone thought a Stafford fumble or pick six (or some other Rams mistake) was coming but that was a special throw by Stafford, especially after the sack on the first down.
McVay decided not to be conservative for once and tried to win it in regulation and Stafford and Kupp rewarded him. Can't believe the Bucs blitzed on that deep shot and left Winfield to cover Kupp, but the damage might've been done on the previous play. Looked like the defender fell down and Kupp just about got out of bounds. Had he not, the Rams might've not had time for a pass in the field of play. But Kupp's heads up play set up the long pass. Kudos.