Shuichi Murata, Terrmel Sledge and Kazuya Fujita each drove in a pair of runs and Shimizu shut down the Hawks' offense as the Stars blanked Softbank 8-0 at Yokohama Stadium, improving to 4-5 in interleague play.
Shimizu, who spent the first 10 years of his career in the Pacific League with the Chiba Lotte Marines before switching bays prior to this season, improved to 5-3. He struck out three and walked two in his 132-pitch outing.
The BayStars struck early, putting two runs on the board in the home half of the first frame. Cleanup-hitter Murata hit a slow roller through the right side of the infield with two men on and one out to open the scoring.
Hawks starter Sho Iwasaki then walked Sledge to load the bases. Iwasaki got Jose Castillo to fly out to center for the second out, a ball not quite deep enough to score the runner from third, before Tatsuya Shimozono drew a bases-loaded walk to plate the second run.
In the bottom of the second, the Yokohamans got to Iwasaki again, this time with Seiichi Uchikawa punching an RBI single through the right side. Uchikawa was thrown out trying to take second on the play, but the run counted and the BayStars had a 3-0 lead.
Meanwhile, veteran right-hander Shimizu just kept plugging along. The only Hawk really hitting him hard was veteran outfielder Hitoshi Tamura, who was 3-for-4 with two doubles. Tamura also reached on an error.
Yokohama broke it open with a three-run seventh inning off Hawks reliever Keisuke Katto before adding two more in the eighth. In the seventh, Murata singled to score Uchikawa from second before Sledge went opposite-field to left off Katto for a two-run homer, his 12th of the season. Murata had three hits Tuesday while Uchikawa was 2-for-4 on the evening with a walk to up his average to .322.
Fujita stroked a sharp two-run single off the first baseman's glove with the bases loaded in the eighth to add the final two runs. Those runs were charged to right-handed reliever Yuki Kume. Fujita, who is hitting .380, had two singles on the night while leadoff-hitter Takehiro Ishikawa was a constant thorn in the Hawks' side with a couple of doubles and a walk.
Iwasaki (0-1) took the loss. He allowed three runs on four hits and three walks over two innings.
Elsewhere, the Hanshin Tigers blanked the Lotte Marines 8-0 at Koshien Stadium. At Mazda Zoom-Zoom Stadium, the Seibu Lions defeated the Hiroshima Carp 10-7.