Police chased down an ex-con after they saw him allegedly attempt to rob a man in Midtown on Friday — and charged him with six robberies in broad daylight over the last two months — including two in Central Park.

Cecil Richardson, 55, was seen by plainclothes cops demanding money from a man on Fifth Avenue near 52nd Street, cops said.

He ran two blocks and then hopped in a cab, but was busted when it got stuck in traffic.

Richardson’s crime spree began April 10, when he pretended he had a weapon in his pocket and took $20 off a victim leaving the Central Park Zoo, according to cops.

He followed that up with five more robberies, including another in Central Park where he stole $18 from a 16-year-old boy sitting on a bench near 79th Street and East Drive on May 29, cops said.

The other thefts were all in Midtown — and Richardson allegedly threatened to hurt most of those victims if they didn’t turn over their cash — in one case $300.

Richardson lives in the notorious Kips Bay homeless shelter which has housed dozens of sex offenders, including one charged with raping a woman in a bar.

He has a record of 13 prior arrests for robbery and had been paroled in March.

His arrest came hours before two muggers strong-armed a 28-year-old man in Central Park near 105th Street and 5th Avenue at about 10:45 p.m. Friday, cops said.

The two robbers made off with $30 and were still at large early Saturday.

There were 22 robberies and grand larcenies in Central Park between January and June of this year., according to the NYPD statistics.