Seldom-used utility infielder Koki Yamashita lifted the Yokohama BayStars to a 4-3, 10th-inning, walk-off win against the Tohoku Rakuten Golden Eagles on Thursday, singling in the winning run in his first at-bat of the season.

Yamashita, a fifth-round pick by the BayStars in 2014, had batted just 161 times in three pro seasons. He entered the game as a defensive replacement. With two outs and an 0-2 count against lefty Yuki Matsui, Yamashita’s fly to right got over the head of right fielder Carlos Peguero and scored Masayuki Kuwahara from second.

“Up to this point, I’ve only been a burden to the team,” Yamashita said. “Last year was so hard, that I vowed to do well this year. Now that I have, I’m so happy.”

The game started as a tantalizing pitchers’ duel between veteran Eagles right-hander Takayuki Kishi and BayStars rookie lefty Katsuki Azuma. Both allowed three runs, Kishi over nine innings, Azuma over 7-1/3.

“Those two pitchers were unbelievable,” BayStars manager Alex Ramirez said. “He (Azuma) pitched a tremendous game. It’s not easy to pitch against Kishi.”

Peguero opened the scoring in the fourth, hitting his 13th home run of the season clean out of Yokohama Stadium with two outs and none on.

Yokohama briefly seized the lead in the bottom of the sixth, when rookie Kazuki Kamizato singled with two outs and scored on Toshiro Miyazaki’s ninth home run. But Peguero manufactured a tying run in the top of the sixth.

The speedy 192-cm outfielder beat out an infield single, stole his first base of the season and scored on Takero Okajima’s one out single up the middle. Rookie Kazuki Tanaka homered off Azuma in the eighth to put the visitors in front.

Kishi, who stayed in to finish the game after throwing 98 pitches through eight, needed to throw 11 pitches to put away the pesky Kamizato for the first out. After 118 pitches, Kishi was one out away from a complete game. But the right-hander fell behind Yoshitomo Tsutsugo, and the BayStars cleanup hitter pulled a 3-1 pitch into the right field stands to tie it.

Closer Yasuaki Yamasaki (1-1), Yokohama’s fourth pitcher, entered the tie game in the 10th and overcame a leadoff walk and a two-out, bases-loaded jam to earn the win.

Matsui (0-4) struck out the first two batters he faced before Kuwahara’s pinch-hit double kept the inning alive and set the stage for Yamashita’s heroics.

Lions 12, Carp 7

At Hiroshima’s Mazda Stadium, in a clash of league leaders, Seibu took the rubber match against two-time defending Central League champion Hiroshima after delivering a 10-run, second-inning knockout blow against starter Kazuki Yabuta (2-1).

Fighters 4, Giants 2

At Tokyo Dome, Toru Murata (3-1) allowed two runs in six-plus innings, while Brandon Laird and Sho Nakata each drove in two runs in Hokkaido Nippon Ham’s win over Yomiuri.

Murata, drafted first by the Giants in 2007, never pitched for Yomiuri’s top team but joined the Fighters after six seasons in the Cleveland Indians’ organization. Two of his four career wins in Japan are against Yomiuri.

Dragons 9, Buffaloes 2

At Nagoya Dome, Kazuki Yoshimi (2-1) allowed two runs over eight innings, and Shuhei Takahashi went 3-for-4 with three doubles and three RBIs as Chunichi avoided being swept at home by Orix.

Hawks 5, Tigers 2

At Koshien Stadium, Fukuoka SoftBank hammered Hanshin reliever Suguru Iwazaki for four runs in the eighth inning after Tigers starter Takumi Akiyama (4-5) held the Hawks to a run over seven innings only to take the loss.

Swallows 3, Marines 1

At Tokyo’s Jingu Stadium, submarine righty Hirofumi Yamanaka pitched out of trouble repeatedly to keep Tokyo Yakult in the game through five innings, and Keiji Obiki’s two-run, seventh-inning double broke a 1-1 tie in a win over Chiba Lotte.