Michael Lamb will announce Monday his plans to quit the Pittsburgh’s Democratic mayoral primary. A source close to the City Controller cited his embarrassing performance Saturday night in a brawl outside the White Eagle Inn on Carson St.

“Mike thought he had a strong base on the southside, that he could count on voters’ support down there,” said the source. “But to his dismay he heard most of them cheering for Jack [Wagner].”

The two entered the establishment around 10:45pm on Saturday. A police report said the incident started over the use of a pool table and escalated from there.

Lamb had been running in third place behind Wagner and City Councilman Bill Peduto in most polls. He was made to split his south hills political base with Wagner.

Wagner, the former Pa. Auditor General, has a long resume and mean left hook.

Lamb’s decision complicates the picture for Peduto, who spent Saturday night nursing a Long Island iced tea at Cappy’s in Shadyside.