CINCINNATI -- Before the game, Dusty Baker didn't know who his closer would be. The Cincinnati Reds manager's eventual choice turned out just right.
Shin-Soo Choo scored the decisive run in the eighth inning on Arizona's fourth wild pitch of the game.
Choo scored both Cincinnati runs, helping the Reds to their third win in the four-game series. Cincinnati (73-55) improved to a season-high 18 games over .500 and increased its lead over Arizona to seven games in the race for the National League's second wild-card playoff spot.
Choo singled to lead off the eighth against reliever Eury De La Rosa (0-1) and moved to second when De La Rosa's pickoff attempt rolled away from first baseman Paul Goldschmidt. Todd Frazier sacrificed Choo to third, and Choo scored when ball four to Joey Votto was a wild pitch.
Mat Latos (13-4) went eight innings and earned the win, despite getting sick before he took the mound. In his previous three starts, Latos had received only five runs of offensive support.
Baker was forced to use his closer Aroldis Chapman for two innings Wednesday night, making him unavailable Thursday. So LeCure was given the chance to earn his first major league save.
"Sam is our utility guy," Baker said. "He can go long or short. He has a lot of guts."
Latos made the most of two runs on Thursday, allowing just one run and five hits to Arizona. Latos struck out seven, didn't walk anyone, and hit one batter with a pitch.
"I was sick right before the first inning," said Latos, who couldn't even keep water down. "I was sick again in the fifth inning. It's gone now but I didn't have anything left in the tank."
Latos managed to save the bullpen.
"Latos gave us what we wanted," Baker said. "A security guard told me he was vomiting underneath the stands."
Arizona starter Trevor Cahill, in his second start since coming off the disabled list, allowed four hits and one run. He walked three, struck out seven and threw three wild pitches -- all in the third inning.
"He struggled that inning," Arizona manager Kirk Gibson said. "They scored two runs on four wild pitches and an error. It's very frustrating, disappointing."
Cahill allowed two hits but still faced the minimum 12 batters over his final four innings, with help from a caught stealing and a double-play ball.
In the third, the Reds put runners on second and third with one out. Brandon Phillips cashed in the opportunity with a run-scoring groundout for a 1-0 lead. Cahill entered the game with 11 wild pitches this season, and now has a major league-high 14.
The Diamondbacks took a more conventional route in getting even 1-1 in fourth. Adam Eaton and Goldschmidt led off with singles, Arizona's first hits off of Latos. Martin Prado hit into a double play, but Aaron Hill rapped a sharp one-hopper that third baseman Frazier couldn't handle. Hill was credited with a run-scoring infield hit.
LeCure told himself he needed three outs like any other inning.
"I didn't want to even let myself think of being the closer. I knew there was a possibility," LeCure said. "Chapman is our closer but I did tell him to watch out."
Baker selected LeCure because he is fearless.
"He doesn't have the best stuff, but he's not afraid," Baker said. "Sam was the best man. He knows how to pitch. I knew he wouldn't get rattled if there were runners on."
Cincinnati RHP Jonathan Broxton is expected to have surgery after he was placed on the disabled list with a strained right forearm. ... The Reds moved RHP Johnny Cueto to the 60-day disabled list to open a roster spot for RHP Nick Christiani, who was called up from Triple-A Louisville. ... Arizona C Miguel Montero was 1-for-2 with a double and a walk. INF Willie Bloomquist was 2-for-3 with a run scored on Wednesday while on rehab assignments with the team's rookie-level Arizona League affiliate. ... LHP Wade Miley (9-8) is Arizona's scheduled starter in Friday's opener of a three-game series at Philadelphia. RHP Homer Bailey (8-10) is due to start at home for the Reds against Milwaukee.