In the clip, Amelia Doris, 40, flees the scene with two children as the victim, Linda Lancaster, aged in her sixties, lies stunned on the ground nursing a head wound.
People rush over to helper her, while Doris glances back at the victim and then leaves on foot holding the hands of two young children.
Doris was due to stand trial at Southwark Crown Court, but on Tuesday, January 5, pleaded guilty to inflicting actual bodily harm in Vauxhall Bridge Road, Pimlico in the incident on May 29, 2019.
She also pleaded guilty to the racially aggravated assault of Ms Lancaster, while the more serious charge of attempted grievous bodily harm was dropped, Mirror Online reports.
Doris was dubbed the "Pimlico Pusher" when police first released the shocking video in an appeal for information following the assault.
Police said she had used a "shoulder barge" to knock Ms Lancaster towards the road.
The pair had argued in the Tesco Express several streets away, with Ms Lancaster claimed Doris also barged her at the time of the row.
Detective Constable Samantha Edwards said: "This was an unprovoked assault which could have had much more serious consequences.
"It goes without saying that the victim has been deeply affected emotionally by this whole incident."
Doris will be sentenced on February 8.
This comes after a jogger was dubbed the "Putney Pusher" after shoving a woman in front of a bus in 2017 – with police forced to give up the search when nobody identified him from CCTV.
Oliver Salbris, the bus driver, managed to stop just in time and told The Sunday Times: "The consequences would have been terrible for her – and for me."
He said the jogger "looked like he was doing it on purpose".