One of the three youths convicted of the stabbing murder of 16-year-old Ben Kinsella lost a Court of Appeal challenge against his 19-year minimum term today.
Juress Kika, 19, had his case thrown out by the Lord Chief Justice, Lord Judge, sitting with two other judges in London.
Kika, Jade Braithwaite, 18, and Michael Alleyne, 20, from London, were convicted of murder at the Old Bailey in June.
Ben, the brother of former EastEnders actress Brooke Kinsella, had been to a bar with friends to celebrate the end of their GCSE exams when a row broke out in Islington, north London, on June 29 last year.
The judges rejected argument on behalf of Kika that his sentence was manifestly excessive.
Ben's father George said: "We are really pleased with the outcome today."
His mother Deborah commented: "We would like to thank the three judges."
Lord Judge said Ben, who was stabbed 11 times, was a "wholly innocent" young man who had been "hunted down".
He was "mercilessly" murdered in revenge for "an insignificant slight for which he bore not the slightest responsibility".
The judge, sitting with Mr Justice Penry-Davey and Mr Justice Henriques, said the minimum term imposed in Kika's case could not "remotely" be described as excessive.
Lord Judge, who also rejected sentence appeals by two other young men jailed for knife murders, has issued a number of warnings recently that offenders face tough sentences for such crimes - and repeated his warning again today.
He said: "We repeat and, until the message is heeded we shall go on repeating, that anyone who goes into a public place armed with a knife, or any other weapon, and uses it to kill or cause injury, and who is brought to justice, must anticipate condign punishment."
Referring to the applications before the court, Lord Judge said: "These three cases involve three individual victims - three young men, all utterly innocent, not seeking trouble, cut down in the street, their lives brought to untimely ends."
The result was "desolate and devastated" parents who were left "grieving and mourning and lamenting that their sons will not become the men they would have been".
He added that deaths in such circumstances "outrage and horrify" the community as a whole.
Of Ben, he commented: "He was a wholly innocent victim... He did not say or do anything which could be misinterpreted as provocation.
"All that this boy wanted to do was to get away from trouble.
"But - we cannot mince words - he was cut down before he could reach safety."
Lord Judge said: "He was left to die. The three assailants made off without a moment's thought for him, just intent on making their escape."