A city starving for a postseason winner went to bed hungry Thursday with only disappointment to chew on in the winter months ahead.

The Cincinnati Reds, who last won a playoff series in 1995 when cell phones were the size of baseball bats, completed an epic collapse with a 6-4 loss to the San Francisco Giants in Game 5 of the National League Division Series.

The Reds became the first National League team to blow a 2-0 lead in the NLDS, and they did it by losing three straight at Great American Ball Park. Scott Rolen, the oldest player on a young club, struck out to end the game with the tying run on first.

“You get tired of the disappointments,” Reds manager Dusty Baker said. “Then you get over it. But it hurts big-time.”

Although the Reds made some noise in the later innings, this game was decided when Buster Posey hit a grand slam in the fifth. That gave the Giants a 6-0 lead and shocked fans whose two professional sports teams — the Reds and Bengals — have combined to go 38 years without advancing past the first round of the postseason.

“I really don’t like saying there are moments in games that totally shift momentum,” Reds first baseman Joey Votto said, “but when Buster hit that grand slam — I mean six runs is so difficult to come back from, and that we almost came back is pretty impressive — he totally broke our back with that swing.”

Posey’s slam brought a sudden end to the start of Mat Latos, who had cruised through four innings.

“I let down everybody,” Latos said. “I let down the team, the front office, the fans, everybody. I let things get to me. That’s 100 percent on me.”

Latos unraveled in the fifth, first giving up a single to Gregor Blanco and then a triple to Brandon Crawford.

With one out and Crawford at third, Zack Cozart fielded a grounder at shortstop and couldn’t decide whether to throw home or to first. He dropped the ball while making up his mind, and the Giants led 2-0.

After Pablo Sandoval singled to load the bases, Posey came up. He was 1-for-10 in the last three games.

“I was trying to make sure I got that run in from third,” Posey said. “I chased a 2-1 pitch and really just told myself to see the ball. I was able to get a good pitch in the zone and got the barrel on it, and good things happened.”

The Reds outhit the Giants 12-9 but left 11 men on base. The Reds had the tying run at the plate in the sixth, the seventh and the eighth.

In the ninth, the storybook ending eluded Cincinnati. With two runners on and one out, Jay Bruce battled Sergio Romo for 12 pitches, fouling off eight, before flying out. Rolen fanned one batter later.

“That Bruce at-bat was unbelievable,” Baker said. “That was sheer determination.”