Morrison stepped and threw to Robinson Cano, who applied the tag as Young Jr. dove into second. Umpire Doug Eddings ruled him safe.
Manager Lloyd McClendon chose to challenge the call, but after a 1-minute, 51-second review, the call stood and Young Jr. was safe.
Still batting, Murphy followed with a double down the left-field line to score Young Jr. and stake New York to an early 1-0 lead.
It wasn't the last time a replay review went New York's way Wednesday.
In the bottom of the eighth inning, manager Terry Collins successfully challenged a safe call at first base. On the play, pinch-hitter Willie Bloomquist appeared to beat out an infield single, as a runner scored from third to cut the lead to 3-2.
But after another replay review, it was ruled that the throw from shortstop Eric Campbell barely beat Bloomquist to the bag. The run still counted, but the call proved pivotal when Endy Chavez followed by striking out with a runner on third base to end Seattle's rally.
Adam Lewis is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.