A former Chicago Police officer broke down crying at her perjury trial Wednesday, testifying that she never lied under oath about being struck by a glass bottle while driving to work on the South Side two years ago.

Sylshina London maintained her previous testimony that she was driving west on 79th near Vincennes in her white Lexus when a woman in another vehicle threw a glass bottle that hit her in the face in March 2010.

Debra Green was convicted of misdemeanor battery for tossing the bottle after becoming upset with London, whom she had never met, for weaving in and out of her sister’s funeral procession.

Green’s conviction was thrown out after video from a police camera affixed to a light pole showed London’s car window was seemingly rolled up as the two cars were briefly parallel at the intersection where London had earlier claimed she was struck.

London was subsequently charged with felony perjury.

London, who resigned from the police department after serving nine years, combatted the accusations Wednesday, claiming the video only showed the third bottle Green threw at her. The object appeared to have bounced off London’s car in the grainy video footage shown in Cook County Judge Joseph Claps’ courtroom.

London, 37, said the first bottle, thrown east from that location, hit her face — after which she closed her window and called police.

When asked by prosecutor LuAnn Snow why she never mentioned the other two bottles allegedly thrown by Green at Green’s 2010 battery trial, London said an assistant state’s attorney advised her to limit her testimony.

London became emotional when she was pressed about why a complaint she signed shortly after the incident stated the bottle hit her face at 79th and Vincennes, countering her claim Wednesday that she was attacked just east of that location.

“It was shocking . . . I didn’t think ‘I better get an address,’ ” she said.

Earlier Wednesday, Green, 32, testified that she didn’t throw anything at London but merely pointed to an orange funeral sticker while the two cars were adjacent and said, “It’s a funeral. It’s a funeral.”

The bench trial will resume before Claps Jan. 4.