Guilherme Messias da Silva, 21, was on his last order of the night when two cars sped down Railton Road and one ploughed into his moped.
Drill artist Lamar Scott, 27 — known as Perm — leapt out of the car which had crashed into the takeaway rider, but was gunned down at around 7.50pm on Sunday.
Speaking from her home in Brazil, Mr da Silva’s mother Rosângela Messias de Sousa, 46, said: “I went into despair, screamed, fainted. It’s very sad, my heart is bleeding. It hurts everything.”
She told TV news channel G1 Goias that her son was “cheerful, outgoing and smiling”.
Ms De Sousa said she made daily calls to her youngest son, who moved to the UK two years ago, in an attempt to stay in touch despite the distance.
But their conversation on Sunday morning was cut short due to the quality of the signal.
Ms De Sousa learned of his death through close friends. The family are now looking for ways to transfer his body back to their hometown of Petrolina de Goias near the Brazilian capital Brasilia.
His stepfather Cirilo Antonio Machado, 66, added of Mr Da Silva’s death: “They hit him at the time of his escape.
“He was very polite, sweet, full of friendships and hardworking.”
Mr Scott was the son of boxer Dillian Whyte’s promoter, Dean Whyte. The heavyweight, who lost to Tyson Fury at Wembley in April, shared tributes on Instagram yesterday.
Friends said he had links with the ClapTown rap group, which is known to have feuds with neighbouring gangs.
The deaths come just five days after two other young men were gunned down at an Ilford terraced house.
This follows a spate of shootings since July in which three men died in separate attacks in six days.
Before these killings, up until July 19 this year, there had been no firearms deaths in London for nine months since October 31 last year.
A Deliveroo spokesman said: “This is an incredibly tragic incident and our hearts go out to the friends and family of those who have lost their lives.
“We are as shocked and saddened that such awful events can take place in one of our local communities and we have offered to support the police however we can.”