The brawl held up traffic for four minutes before one group was chased away.
Local Khun Itiphat said: “I could hear them squealing.
“Then they ran on to the road and began wrestling.”
One monkey troop lives in a nearby ruined temple, the other in an abandoned cinema in Lopburi, Thailand.
Vet Supakarn Kaewchot said: “They are so used to having tourists feed them.
“With tourists gone, they’ve more aggressive.
“They’re invading buildings and forcing people to flee their homes.”
Locals think the monkeys are lucky and hold a festival for them annually.
Officials have also tried to control the number of monkeys by rolling out mass sterilisation programs.