With their chances of a playoff spot decreasing daily, Hiroshima's hitters remained in a funk that saw the Carp lose their fourth straight and fall three games out of the final playoff spot with 10 games to play.
Giants right-hander Yuya Kubo threw one-hit ball over eight scoreless innings and Hayato Sakamoto singled home the only run in the 10th inning in a 1-0 victory at Tokyo Dome.
It was the ninth straight win for the Giants, who clinched their third straight Central League title on Thursday.
In addition to his one hit, Kubo hit a batter and issued two walks--both to Carp pitcher Kenta Maeda, who matched Kubo's eight shutout innings.
"He gave up those two meaningless walks, but he had good movement and pitched outstanding," Giants manager Tatsunori Hara said of his starter.
Kubo came out for a pinch-hitter in the bottom of the eighth, but Shota Kimura pitched a 1-2-3 ninth, and an excellent play by Sakamoto at short helped lefty Norihito Kaneto stop the Carp in the 10th.
With the go-ahead run on second and one out, Kaneto entered the game and got a slow bouncer to the left of the mound. Sakamoto charged and made an off-balance throw across his body, getting the ball to first in time to draw an out call.
Kaneto (1-0) got a routine grounder to second and collected the win when pinch-runner Takahiro Suzuki scored from second on Sakamoto's two-out sayonara single to left.
Sakamoto, whose base-running played a crucial role in Friday night's 3-2 come-from-behind win over the Carp, fell behind Ryuji Yokoyama (3-8) 0-2 before stroking a low 2-2 forkball into left for the game-winner.
"I have no objections to his play at all," Hara said regarding his shortstop's continued clutch effort.
The Carp got a clutch effort from Maeda. In a must-win situation before a crowd of 43,433 in enemy territory, the 21-year-old Maeda allowed three hits and walked a pair of batters, while striking out four.
Mike Schultz worked a 1-2-3 ninth to send the game into extra innings, but the Giants refused to go quietly.
Captain Shinnosuke Abe singled to open the 10th and came out so Suzuki could run. A groundout that advanced the runner, a strikeout and a four-pitch walk to pinch-hitter Yoshitomo Tani brought up Sakamoto, who singled to left center.
With two outs, Suzuki's speed gave the Carp no chance to cut off the run as the Giants won a 1-0 sayonara game for the first time in over five years and improved to 44 games over .500 for the first time in 19 years.
The Carp leadoff men reached base in four different innings but the batters coming up continued to struggle.
"We played good baseball, but we didn't have enough offensively to get it done, which has been a problem for us all year," said Carp manager Marty Brown, whose club was assured of its eighth-straight losing season.
"We didn't swing the bats, our approach didn't change and we didn't make adjustments."
An error gave the Carp a chance to score first. With two down in the first inning, a rushed throw from third baseman Michihiro Ogasawara sailed into no-man's land, allowing Andy Phillips to go to second. Struggling cleanup hitter Kenta Kurihara, however, struck out to end the inning. Kurihara went 0-for-4 and has not hit safely in 18 straight at-bats.
Ogasawara gave his own team a scoring chance in the bottom of the first with a two-out double. Alex Ramirez followed with a hot bouncer to Kurihara at first, but the Golden Glove winner made a neat grab behind the bag to end the threat.
The Carp wasted scoring opportunities in the sixth and eighth, and Soichiro Amaya beat out an infield single to open the 10th, but Sakamoto's defense helped turn the visitors away hungry.