The City of Rockville yesterday closed off direct entry from a city-owned parking lot to the shopping mall known as The Commons at Courthouse Square, a move designed to press the city's claim for over $800,000 in back payments from the mall's owners.

Earlier in the day, a Montgomery County Circuit Court Judge had denied a request from owners of the financially troubled mall, Rockville Redevelopment Associates, to block the city's move pending a hearing. In addition to closing off doors and escalators, the city also cut off free parking to mall customers.

The city contends that the mall, which opened nine years ago and was intended to help revitalize downtown Rockville, is more than $800,000 behind in payments related to the city's parking garage beneath it, according to city attorney Roger Titus.

Rockville has received no payment of any kind from the mall since November 1979, Titus said. In April 1980, it gave the mall 60 days to pay, he said, and after that the city reserved the right to take action as it saw fit.

In return for payments, the city had previously granted free parking to mall customers who presented tickets stamped by mall merchants.

Currently many of the mall's shops are abandoned and boarded up. Current tenants have repeatedly received notices from water and electric suppliers threatening that service was about to be cut off because the mall's owners were behind in payments, according to Rockville and Montgomery County officials.

In addition to the money it owes the city, RRA is in default on a first mortgage held by the New York State Teachers Retirement System and owes Montgomery County $238,000 in back taxes, according to a company official.

An official in the office of Sulzberger-Rolfe Inc., the management company that runs the mall for RRA, said that yesterday's action by officials would hurt business but said lunch-time shoppers from surrounding office buildings -- who constitute most of the mall's customers -- would not be affected.