Nick Hundley hit a two-run double with two outs in the eighth inning and the San Diego Padres beat Cincinnati 4-2 Tuesday night, handing the Reds their fifth straight loss.
Latos faced his former team for the second time since he was dealt from San Diego in a five-player trade on Dec. 17, 2011.
"It's rough," Latos said of the losing streak. "That's for sure. We have such a good ballclub. I can't think of the one word that describes it. I can't think of a word, but it's miserable. I don't know, we're such a good ballclub. We shouldn't be losing ballgames."
Latos and San Diego's Edinson Volquez were matched up for the second time since the five-player trade. Neither got a decision.
Latos went six innings, allowing two runs and two six hits, striking out six and walking two.
Volquez went 6 1-3, allowing two runs and four hits, walking five and striking out three.
"I got behind a lot of guys," Latos said. "It's not what you want to try and do. I wasn't getting that first-pitch strike."
The Reds matched their longest losing streak of the season.
Said manager Dusty Baker: "We only have two choices - go home or come back another day and fight. No two days are the same."
Will Venable, who scored the go-ahead run on Hundley's' hit, went 3 for 3 with a walk, a run scored and an RBI.
Venable singled to right with one out in the eighth against Manny Parra (1-2). Sam LeCure came on and allowed a single to rookie Jedd Gyorko before striking out pinch-hitter Chris Denorfia. Hundley then doubled down the left-field line.
Parra hadn't allowed a run since June 7, a streak of 19 games.
Dale Thayer (1-3) pitched 1 1-3 innings for the win. Huston Street pitched the ninth for his 20th save in 21 chances.
The Reds scored single runs in the second and sixth innings, and the Padres matched them each time.
In the second, Devin Mesoraco's high chopper to third scored Jay Bruce, who was aboard on a leadoff single. San Diego tied it when Logan Forsythe's groundout brought in Yonder Alonso, who hit a leadoff single and advanced on Venable's double.
The Reds took advantage of Volquez's wildness to go ahead 2-1 in the sixth. Joey Votto and Brandon Phillips drew consecutive walks and Votto scored on Bruce's single to right.
San Diego came back and tied it when Jesus Guzman beat out an infield single and scored on Venable's one-out double to center.
NOTES: Reds OF Shin-Soo Choo returned to the starting lineup after missing Monday's game with a sore left ankle. Choo started in LF instead of CF to cut down running and possibly re-injuring his ankle. "This is Yellowstone National Park out here," manager Dusty Baker said, referring to roomy confines of Petco Park. "You need some good fresh legs." ... OF Ryan Ludwick remains "a ways off" from returning, Baker said. Ludwick, 2 for 12 with one RBI in five rehab appearances in the minors, needs at least 50 at-bats before returning to Cincinnati, Baker said. ... Padres CF Cameron Maybin began a rehab assignment with Tucson on Tuesday night. He was placed on the 15-day disabled list on June 12, retroactive to June 10, with a strained left knee. Earlier this year, he spent time on the DL with a right wrist impingement. Manager Bud Black said the rehab assignment will be significantly longer than a week to 10 days. ... The series concludes Wednesday afternoon when Cincinnati's Homer Bailey (5-10, 3.77 ERA) faces lefty Eric Stults (8-9, 3.65). ... Padres LF Carlos Quentin left the game after tweaking his right knee.