Elsewhere in the Padres' system, Luis Urias had a four-hit game for Class A Advanced Lake Elsinore to take the California League batting lead and fourth-round Draft pick Joey Lucchesi had another strong start for short-season Class A Tri-City.
Simmons (2.17 earned run average) allowed the one hit at San Antonio, with four walks and six strikeouts in six innings. The 5-foot-9, 170-pound Simmons, 28, was signed by the Padres on May 24 after he was released from the Arizona Diamondbacks' system.
Right-hander T.J. Weir (3.21 ERA) followed Simmons and struck out two in two perfect innings. Left-hander Kyle McGrath (1-2, 1.51 ERA) struck out two in a perfect ninth to get the win.
Center fielder Cordero (.318) gave the Missions the walk-off win with his scoreless tie-breaking homer in the ninth.
Cordero was 2-for-4, as the Missions improved to 25-23 in the second half of the Texas League season and moved to 47-71 overall.
Right fielder Nick Schulz (.281) and shortstop River Stevens (.257) were each 1-for-3.
At Fort Wayne, Allen, 22, was 2-for-5 with a double and an RBI while extending his streak and raising his batting average to .323. Allen's 24-game hitting streak eclipses the old TinCaps record of 23 straight games, set by former Padres third baseman Sean Burroughs in 1999. Allen was the Padres' fourth-round pick in the 2015 Draft.
Allen was part of an 18-hit attack, as Fort Wayne (19-28, 55-62) routed Bowling Green, 13-5, in the Indiana city.
Four TinCaps had three hits. Third baseman Carlos Belen (.229) was 3-for-4 with his 10th homer, three RBIs and three runs scored. Shortstop Ruddy Giron (.222) was 3-for-5 with a double and three runs scored. First baseman Brad Zunica (.253) was 3-for-4 with two doubles, two RBIs and two runs scored. And second baseman Peter Van Gansen (.220) was 3-for-5 with two RBIs and a run scored.
Left fielder Tyler Moore (.257) was 2-for-6 with a double, two RBIs and two runs scored. Right fielder Jose Carlos Urena (.212) was 1-for-1 with two RBIs.
Right-hander Emmanuel Ramirez (2-0, 4.34 ERA) started and allowed three runs on six hits with five strikeouts in five innings. Right-hander Will Stillman (5.79 ERA) allowed two runs on four hits and a walk with a strikeout in 1 1/3 innings. Left-hander Elvin Liriano (2.95) allowed two hits with four strikeouts in 2 2/3 scoreless innings.
Urias (.327) was 4-for-5 with an RBI for Lake Elsinore and leads the California League with a .327 batting average. Lucchesi lowered his ERA to 1.61 with a fourth straight scoreless outing.
There were several moves made on Friday.
Catcher Marcus Greene Jr., Allen's backup at Fort Wayne, went on the disabled list with a concussion suffered Thursday night, when he was struck by a foul tip. Catcher Hunter Redman was promoted from Tri-City to Fort Wayne. Right-handed pitcher Trey Wingenter was transferred from San Antonio to Lake Elsinore.
Around the farm:
TRIPLE-A EL PASO (65-55) - OKLAHOMA CITY 8, Chihuahuas 4: Left fielder Patrick Kivlehan (.247) was 3-for-4, while second baseman Carlos Asuaje (.322) was 1-for-3 with a walk and a run scored. Pinch-hitter Taylor Lindsey (.282) had a double and a run scored. Righty Daniel McCutchen (9-9, 6.58 ERA) started and allowed eight runs (seven earned) on nine hits and three walks with seven strikeouts in five innings. Right-hander Jason Jester (8.53 ERA) pitched a perfect inning, while righty Michael Dimock (4.35 ERA) struck out the side in his one inning. Right-hander Kevin Quackenbush (2.08 ERA) allowed two hits with two strikeouts in a scoreless inning.
CLASS A LAKE ELSINORE (28-20, 60-68) - BAKERSFIELD 4, Storm 2: Left fielder Taylor Kohlwey was 2-for-5 with a run scored in his Storm debut. Third baseman Ty France (.307) was 2-for-5 with an RBI, while center fielder Michael Gettys (.302) was 2-for-4. Right fielder Franmil Reyes (.257) was 2-for-4 with a double. Right-hander Brett Kennedy (5-8, 3.29 ERA) started and allowed three runs on six hits and two walks with nine strikeouts in 6 1/3 innings. Righty Ben Paullus (4.75 ERA) allowed a run on two hits with two strikeouts in 1 2/3 innings.
SHORT-SEASON CLASS A TRI-CITY (6-9, 25-28) - Dust Devils 5, BOISE 3: Catcher Wilfri De La Cruz (.321) had a double and his first homer in four at-bats to drive in two runs. Center fielder Buddy Reed (.222) was 2-for-4 with a double and a run scored, while shortstop Chris Baker (.302) had a double with an RBI and a run scored. Righty Braxton Lorenzini (3-3, 7.18 ERA) followed Lucchesi and allowed a run on two hits and two walks with a strikeout in three innings, and right-hander Phil Monroe (7.27 ERA) allowed two runs on two hits and two walks in two-thirds of an inning. Righty Evan Miller (2.25 ERA) allowed three hits and two walks with three strikeouts in 2 1/3 scoreless innings.
ARIZONA ROOKIE PADRES (18-24) - Diamondbacks 7, PADRES 3: Right fielder Dayon Olmo (.243) hit his fourth homer and drove in two runs in his four at-bats. Designated hitter Fernando Tatis Jr. (.273) and catcher Jose Lezama (.272) were each 1-for-3 with a walk. Righty Luis Diaz (0-1, 9.00 ERA) allowed two runs (one earned) on two hits and a walk with two strikeouts in an inning on a rehab assignment, while right-hander Trey McNutt (0.00 ERA) started his rehab, allowing two unearned runs on a hit and a walk in one-third of an inning. Righty Juan Arias (9.64 ERA) allowed a hit with two strikeouts in 1 2/3 innings, and right-hander Starlin Cordero (3.27 ERA) allowed an unearned run on two hits and a walk with three strikeouts in two innings. Righty Jonathan Guzman (9.15 ERA) struck out one in a perfect inning, while lefty Ben Scheckler (4.74 ERA) allowed two runs on four hits with a strikeout in three innings.
DOMINICAN SUMMER LEAGUE PADRES (29-30) - Padres 7, ORIOLES-1 1: Second baseman Eguy Rosario (.345) was 1-for-4 with a double, a walk, his 21st stolen base, an RBI and three runs scored. Third baseman Kelvin Alarcon (.274) was 3-for-5 with a steal and a run scored, while shortstop Kelvin Melean (.277) was 2-for-4 with a double, a walk, a steal, an RBI and two runs scored. Right fielder Jaffe Garcia (.254) was 1-for-3 with two walks and two RBIs. Southpaw Jose Cabrera (2.93 ERA) started and allowed two runs on four hits and two walks with five strikeouts in 3 2/3 innings. Righty Luis Martinez (2-1, 12.86 ERA) allowed three walks in 2 1/3 hitless/scoreless innings, while right-hander Miguel Roman (15.00 ERA) allowed a hit and a walk with three strikeouts in 1 2/3 scoreless innings. Righty Eduwin Bencomo (4.66 ERA) struck out three in 1 1/3 perfect innings to get his sixth save.