"We haven't done enough to win," said Mattingly. "We haven't really done anything wrong; just not enough to win."
The loss kept the Dodgers' magic number for clinching the division at 11, after to Arizona's 2-1 win Saturday night at San Francisco.
If the Dodgers are indeed going to be playing October baseball, veteran outfielder Carl Crawford said, the weekend series against Cincinnati is a good indication of how those games might feel.
"These two games are what the playoffs are going to be like," said Crawford. "There's not going to be a lot of runs scored. [The Reds] are trying to battle for a playoff spot, too."
Cincinnati's late-game hero agreed.
"September's the time to step up or shut up," said Frazier. "You forget about what's been going on during the year, and you just have to keep striving to get better."
Wilson (1-1) walked Ryan Ludwick on five pitches to lead off the inning. Ludwick was replaced by speedy rookie Billy Hamilton, as Mattingly and Dodgers assistant athletic trainer Nancy Patterson Flynn came out to the mound to talk to Wilson after noticing the right-hander shaking his arm.
"I'm fine," said Wilson. "[Shaking my arm] is what pitchers do. I'm going to walk a few guys. I just didn't throw a strike."
Hamilton stole second, his fourth steal in four games. Frazier then drove a hit through the right side of the infield. Hamilton sprinted around third and arrived at home plate well ahead of Yasiel Puig's throw.
J.J. Hoover (4-5) worked the 10th for Cincinnati, as the Dodgers managed just one hit over the last five innings.
The game matched two of the National League's best starting pitchers. Zack Greinke came into Saturday with a 14-3 record, while Cincinnati's Mat Latos was 14-5. Greinke survived a rough first inning to outduel Latos and leave with a 3-2 lead.
The Reds scored twice off Greinke during the first inning, but he shut out Cincinnati the rest of the way, retiring nine of the last 10 batters he faced.
"There were no pitches [in the first inning] I'd take back," said Greinke. "They just had good at-bats. They didn't make many mistakes."
Both starters threw 106 pitches -- with Greinke compiling 72 strikeouts to Latos' 70.
Greinke was at his toughest in the fifth inning, when he struck out Jay Bruce and Ludwick with the bases loaded.
Paco Rodriguez, who replaced Greinke to begin the seventh inning, gave up the tying run on a Cesar Izturis double down the left-field line.
"I feel fine," said Rodriguez. "I take responsibility for giving up that run. I'm hard on myself, just like anyone who loves the game."
The first two innings certainly didn't resemble a pitchers' duel, as the teams combined for nine hits off Greinke and Latos. Cincinnati strung together four consecutive singles off Greinke in the first to jump ahead, 2-1. But that lead didn't last long.
Puig reached across the plate to drill a two-out pitch from Latos into the left-field seats for his 15th home run, putting the Dodgers back on top, 3-2. The Dodgers missed an opportunity to extend their lead in the fourth inning when Crawford got hung up between second and third on Adrian Gonzalez's single to right. Greinke was tagged out between third and home to extinguish the threat.
Crawford said he thought Greinke would be trying to score with two out. Greinke said that, taking his own footspeed and Bruce's rifle arm into account, he didn't think it was possible.
"I should have been running with my head up," said Crawford. "I was trying to draw the throw, but I didn't look up to see that [Greinke] had stopped."
"It's going to be tough to get another hit off Latos," said Greinke. "I am sure [Carl] was hoping to get caught in a rundown and let me score. Our best chance was for me to be faster.
"I don't know if it's a mistake or if it's smart baseball, that just didn't work."
Mattingly hopes the smart baseball continues and timely hits arrive soon.
"For a month and a half, we got every big out we needed," said Mattingly. "Today, we got big outs; just not enough hits or enough runs."