Police arrested Comanchero gang boss Mick Murray, 44, in Lysterfield South shortly before 5am on Thursday and later charged him with murder.
He appeared in the Melbourne Magistrates Court hours later and was remanded in custody to return in August.
A second man, a 32-year-old from Hallam, was also arrested and interviewed before being released.
Rasimi, a 51-year-old former associate of drug kingpin Tony Mokbel, was found dead with four bullet wounds to his chest behind the wheel of his silver Peugeot Coupe at Dandenong in March 2019.
Victoria Police Acting Deputy Commissioner, Bob Hill, described Murray's arrest as "one of the most significant" in recent years.
"This arrest is testament not only to the hard work of the homicide squad detectives but the investigators more broadly that preceded them and many investigators from not only the homicide squad but other parts of our squad commands," he said.
"Some criminal groups think they can operate above the law. Time and time again, we prove them wrong.
"These people may be able to avoid law enforcement for a period of time but their judgement day comes eventually."
He said Victoria Police remains committed to tackling organised crime.
Comancheros bikies Richard Ene and Laiseni Kakato were previously charged with murder in connection with Rasimi's death.
They remain in custody and are pleading not guilty.
