Jordy Mercer added to the lead with a two-run homer off Snell in the fifth, putting the Pirates up 4-1.
Snell, who will be the Rays' No. 4 starter, made his fifth appearance (fourth start) of the spring and allowed four runs on seven hits and two walks while striking out three in five innings.
When asked if he'd missed locations on the home runs, Snell smiled: "Is down the middle bad?"
Right-hander Jameson Taillon, the Pirates' No. 2 starter, allowed two runs on four hits and two walks while striking out four over 4 1/3 innings.