Here are a few alternative titles, capturing the same information in different ways:

Focusing on Ohtani:

• Ohtani Launches First Career Splash Hit at Oracle Park
• Shohei Ohtani Makes a Splash: First Oracle Park Homer Clears the Wall
• Ohtani’s Blast Lands in McCovey Cove for First Time
• Ohtani Hits a Splash Hit: A First for Him at Oracle Park

Focusing on the Event:

• Ohtani Goes Deep into McCovey Cove for a Splash Hit
• Splash Hit! Ohtani’s Homer Lands in the Bay at Oracle Park
• Giants See Ohtani Join the Splash Hit Club at Oracle Park

More Descriptive:

• Shohei Ohtani Crushes a Home Run into McCovey Cove
• Ohtani Achieves Rare Feat: Splash Hit at Giants’ Home

The best title will depend on the specific context and target audience.