The 23-year-old right-handed Diaz allowed four hits and a walk over seven scoreless innings in his debut in the Padres' organization for the 2-2 Missions.
Submarining right-hander Eric Yardley allowed a hit in a scoreless eighth, and right-hander Jason Jester completed the shutout as he struck out two in a scoreless ninth, despite allowing three hits.
Shortstop Nelson Ward, who the Padres acquired from Seattle last November in the trade that sent reliever Joaquin Benoit to the Mariners, had a strong all around game. Offensively, Ward was 1-for-4 with a run scored, a RBI and three steals. On defense, he started three double plays.
Class A Advanced Lake Elsinore improved to 3-1 with a 7-6 victory at Rancho Cucamonga, while low Class A Fort Wayne pounded out 18 hits in their second home game to rout Lake County, 14-4.
Center fielder Franchy Cordero (.313) paced Lake Elsinore, going 3-for-4 with a triple, a walk and four runs scored. Designated hitter Franmil Reyes (.133) drove in four runs, although he was only 1-for-5. Left-side infielder Chase Jensen was 2-for-4 with two steals, two runs scored and an RBI. Catcher Jose Ruiz doubled in three at-bats with a walk and a run scored.
Right-hander Michael Kelly started for the Storm and allowed four runs on eight hits and three walks with four strikeouts in four innings.
Right-handed reliever Chris Huffman picked up his second early-season win despite giving up two runs on four hits and a walk with a strikeout in two innings. Right-hander T.J. Weir allowed a hit in two scoreless innings. Right-hander Colby Blueberg pitched a perfect ninth to pick up his second save.
At Fort Wayne, catcher Austin Allen and first baseman Brad Zunica stayed hot for the TinCaps.
Zunica (.600) was 3-for-4 with a double and his second homer in as many games, driving in four runs and scoring three. Allen's average (.786) slipped slightly, although he went 3-for-4 with a double, two RBIs and three runs scored.
Shortstop Ruddy Giron, 19, was 4-for-6 with two doubles, two RBIs and three runs scored. He is hitting .313 after four games. All nine Fort Wayne starters got at least one hit. Center fielder Michael Gettys (.235) was 2-for-6 with an RBI and a run scored. Second baseman Peter Van Gansen (.286) was 2-for-5 with an RBI and two runs scored.
Right-handed starter Jacob Nix allowed four runs on five hits and two walks with a strikeout in 1 2/3 innings. Left-hander Taylor Cox was credited with the win, allowing no runs on three hits with two strikeouts in 2 1/3 scoreless innings.
Left-hander Logan Allen, 18, followed Cox and pitched three scoreless, allowing three hits and a walk with five strikeouts. Right-hander Emmanuel Ramirez finished the game, walking three with four strikeouts in two hitless innings.
Around the farm
TRIPLE-A EL PASO (1-2) - RENO 6, Chihuahuas 1 -- Right-handed starter Justin Hancock allowed five runs (two earned on his own error) on eight hits with four strikeouts in five innings to suffer the loss. Righty Derek Eitel allowed a hit with a strikeout in 1 1/3 scoreless innings. Center fielder Manuel Margot (.182) was 1-for-4 with a steal and a run scored. Right fielder Hunter Renfroe was 1-for-4 with a RBI.