SEOUL, South Korea -- Yoshinobu Yamamoto lasted one inning in his Los Angeles Dodgers debut after signing a record $325 million, 12-year contract, giving up five runs in a 15-11 loss to the San Diego Padres on Thursday.
The 25-year-old right-hander trailed 2-0 after nine pitches and needed 43 pitches to get three outs, leaving with a 45.00 ERA.
San Diego batted around, and Michael Grove relieved Yamamoto with the Dodgers trailing 5-1.
"I feel regret that I just couldn't keep the team in the game from the get-go, so I do feel the responsibility for it," Yamamoto said through an interpreter. "I just got to get ready for the next outing."
Yamamoto (0-1) allowed four hits, walked one, hit a batter and threw a wild pitch. He threw just 23 pitches for strikes, averaging 95.4 mph with his fastball. He tried 14 fastballs, 11 cutters, 10 curveballs and eight splitters.
Xander Bogaerts singled to left on his first pitch, a 96.6 mph fastball over the heart of the plate. Fernando Tatis Jr. was hit by a full-count splitter and Jake Cronenworth tripled into the right-field corner for a 2-0 lead.
Manny Machado walked, bringing pitching coach Mark Prior to the mound 15 pitches in.
Ha-Seong Kim hit a sacrifice fly, a wild pitch advanced Machado and Jurickson Profar struck out on an inside cutter.
Luis Campusano hit a bouncer over third base that got under Max Muncy's glove and went down the line for an RBI double and a 4-0 lead. Tyler Wade hit a run-scoring single to right and rookie Jackson Merrill struck out on an inside curveball.
The Dodgers allowed five runs in the first inning just one time last season.
Yamamoto was a two-time Pacific League MVP in Japan for the Orix Buffaloes. He signed his deal with the Dodgers in December, the largest amount guaranteed to a pitcher.
"Just didn't have the command and so it's not about the stuff," Dodgers manager Dave Roberts said. "When you're a command guy, which he's been his entire career -- his life, and you just misfire, get behind in counts, hit batters, that's just not who he is. ... He's an easy guy that you know he'll bounce back from this."
The Associated Press contributed to this report.