Since 1908, a Red Sox pitcher has driven in three or more runs in a game 94 times.
Rick Porcello is #94, of course. He is also the only Red Sox pitcher to have a 3+-RBI game in the DH-era (now in its 46th year).
The last Boston pitcher to drive in three or more runs was Sonny Siebert, who hit two home runs and had three RBI on September 2, 1971. Earlier that year, in the second game of a June 26, 1971 doubleheader, Siebert knocked in five runs against the Orioles.
Two Red Sox pitchers have driven in six runs in a game.