Apollo/Domain DN416 also is in the race, but I couldn’t find much about it, other than that it was a dual-CPU system, using the second CPU to implement virtual memory (https://en.wikipedia.org/wiki/Apollo/Domain#Models: “This system used two 68000 processors and implemented virtual memory (which the 68000 wasn't theoretically capable of) by stopping one processor when there was a page fault and having the other processor handle the fault, then release the primary processor when the page fault was handled.”)
“The Wicat is one of the first (perhaps even the first) computer to use a Motorola MC68000 processor.”
That page says this system was released in 1981.
https://en.wikipedia.org/wiki/Sun-1 and https://en.wikipedia.org/wiki/IBM_System_9000 both are from may 1982.
Apollo/Domain DN416 also is in the race, but I couldn’t find much about it, other than that it was a dual-CPU system, using the second CPU to implement virtual memory (https://en.wikipedia.org/wiki/Apollo/Domain#Models: “This system used two 68000 processors and implemented virtual memory (which the 68000 wasn't theoretically capable of) by stopping one processor when there was a page fault and having the other processor handle the fault, then release the primary processor when the page fault was handled.”)