The surging Padres offense, which has scored 24 runs in the three games, also got two hits and two RBIs from Chris Denorfia.
Erlin, who didn't walk a batter, had seven strikeouts to match a career high. The Padres pitchers struck out 48 over the four-game series to set a franchise record. They broke their mark of 44 set in 1998 against Montreal.
Miami's Henderson Alvarez (2-3), who was coming off his second shutout of the season and third in his last eight starts, wasn't sharp. He lasted four innings, allowing five runs on seven hits with three walks and two strikeouts.
Erlin had lost four straight decisions before beating the Marlins in his first appearance against them. But it was his second consecutive strong showing after a seven-inning, one-run outing versus the Royals.
In the fourth inning the Padres extended their lead to 2-0 on a RBI single by Alexi Amarista. He drove in Chase Headley - and took second on the throw - after Headley singled and advanced to second on a walk to Yonder Alonso.
With Alonso and Amarista in scoring position, Alvarez induced Erlin to groundout but walked Venable. On a full count, Denorfia produced a two-out, two-run single to left.
Smith followed with a single to center to score Venable and push the Padres cushion to 5-0.
The Marlins rallied in the eighth when Christian Yelich homered, his third of the year. Reed Johnson followed with a single which chased Dale Thayer. Giancarlo Stanton, who earlier extend his hitting streak to a career-best 13 games, singled off Joaquin Benoit.
Jeff Baker's two-run triple to right pulled the Marlins to within 5-3 and when Garrett Jones walked and took second on a wild pitch, the tying run was in scoring position. Baker scored on Adeiny Hechavarria's groundout to second but pinch-hitter Jarrod Saltalamacchia struck out to end the threat.
The Padres scored early when Venable hit his franchise-best 10th career leadoff homer. His 400-foot blast off a 1-0 fastball over the right-field wall was his first home run of the year.
NOTES: Padres SS Everth Cabrera was out of the starting lineup after his wife, Connie, gave birth to their daughter late Saturday night. ... OF Carlos Quentin was to play with Single-A Lake Elsinore on Sunday as he continues his rehabilitation from bruised left knee. Quentin could join the club on its upcoming road trip. ... LHP Casey Kelly threw a bullpen session and will pitch at Double-A San Antonio on Wednesday; he's rebounding from Tommy John surgery. ... Marlins MGR Mike Redmond said he's not sure where RHP Henry Rodriguez fits into the team's bullpen. Rodriguez, who worked the seventh inning, was summoned from Triple-A New Orleans. ... Marlins RHP Tom Koehler (3-2, 1.99) faces Dodgers RHP Dan Haren (4-1, 2.68) on Monday in Los Angeles. ... Padres RHP Andrew Cashner (2-5, 2.86) goes against Reds RHP Mike Leake (2-3, 3.40) in Tuesday's series opener in Cincinnati.