Miguel Vargas also homered for the Dodgers, who took the opener of a three-game series after losing three of their previous four games.
Smith's first career three-homer game was the fourth ever from a Dodgers catcher and the first since Yasmani Grandal accomplished the feat in 2016.
Rhys Hopkins hit a grand slam and Aaron Civale went five innings in his debut with his new club as the National League Central-leading Brewers fell to 2-3 on a seven-game road trip. Civale was acquired Wednesday in a trade with the Tampa Bay Rays.
Astros 13, Twins 12
Jeremy Pena recorded his sixth three-hit game of the season to pace a balanced offensive attack by Houston, who outlasted Minnesota.
The Astros improved to 13-2 over their past 15 games by banging out 16 hits. Pena finished 3-for-5 with three RBIs and three runs, and Yainer Diaz went 2-for-5 with three runs. Houston scored three times in the second, sixth, eighth and ninth innings.
The Twins made it interesting in the bottom of the ninth, scoring seven runs with two outs. Houston closer Josh Hader entered with two outs and surrendered a grand slam to Twins shortstop Carlos Correa. Hader rallied to strike out Manuel Margot for his 15th save.
Padres 10, Diamondbacks 8
Manny Machado's two-run homer in the bottom of the ninth inning lifted San Diego Padres to a win over visiting Arizona.
The Diamondbacks overcame a 7-2 deficit in the top of the ninth thanks to a grand slam from Alek Thomas and a two-run shot from pinch hitter Randal Grichuk, building an 8-7 lead.
In the bottom of the ninth, Jurickson Profar led off with a game-tying homer off Paul Sewald (0-2). After Jake Cronenworth worked a walk, Machado went deep, making a winner of Stephen Kolek (3-0).
Orioles 3, Athletics 2
Albert Suarez pitched six-plus innings of two-run ball, Austin Hays collected three hits on his birthday and Baltimore did all its scoring early to beat hosts Oakland.
Yennier Cano stranded the potential tying run at third base in the eighth and Craig Kimbrel coasted through the ninth, helping the Orioles win for the seventh time in nine games. Suarez (5-2) fanned six and walked one.
Shea Langeliers and Miguel Andujar homered for the A's, who had a three-game winning streak end. Hogan Harris (1-3) gave up three runs, two earned, in five innings.
Mariners 2, Blue Jays 1
Luis Castillo pitched 6 2/3 sterling innings as Seattle defeated visiting Toronto in the opener of a three-game series.
Luke Raley hit a two-run double for the Mariners, who won their second game in a row. Castillo (7-9) allowed one run on two hits with two walks and eight strikeouts.
Kevin Kiermaier homered for the Blue Jays, who fell for the 13th time in 17 games.
