The suspect wasn't the man named by police on Saturday, Tobias Dustin Summers, who cops say is still at-large.
Rather, the arrestee was ID'd as Daniel Martinez, 29:
The West Hills resident was arrested "early Sunday morning" in the 18200 block of Rayen Street in Northridge, the LAPD announced this afternoon.
He was booked on suspicion of kidnapping and was jailed in lieu of $1 million bail, cops said.
Meanwhile, police said they believe Summers, 30, might be in San Diego.
The 10-year-old was discovered missing from her Northridge bedroom Wednesday after mother heard a noise and went to check on her, police said.
She was driven around and taken to one or two places, including an area storage facility, before being dropped off nearly 10 hours later at a Valley Kaiser medical facility, cops said.
Officials indicated she had been attacked and traumatized during the 10-hour ordeal.
Summers was described as an area transient with a record that included allegations of kidnapping and robbery.
The girl said that two men had kidnapped her, police said.
[Added at 1:42 p.m.]: L.A. Sheriff's Department inmate records indicate Martinez was arrested at 4:25 a.m. Sunday by LAPD Robbery Homicide Division detectives.
He's described as 5 feet, 7 inches, 180 pounds with blue eyes.
Also ... cops think Summers might have shaved his head, according to an LAPD statement.