Eichel drew a holding penalty against Larkin 55 seconds into overtime, but Howard made two saves during Buffalo's 4-on-3 power play.
"That was a huge kill, because 3-on-4 is tough to stop," Howard said. "The guys kept lanes open so I could see everything, and they blocked some big shots."
Larkin matched his NHL career high of 10 shots on goal, and Eichel had seven.
"We've played together a lot and we're really close, so it is always fun to play against [Eichel]," Larkin said. "We were matched against each other tonight, and he's tough to handle, but we both made some plays."