The 11-year-old attacker was shot by the moderately wounded guard, while the other was restrained by passengers before police arrived.
The victim suffered stab wounds to his upper body, and was taken to Jerusalem’s Shaare Zedek Medical Centre for treatment.
The wounded attacker was treated by paramedics and taken to the Hadassah Ein Kerem hospital, where he remains in a serious condition.
Avi Cohen, the captain of the local police station, said that “the swift and determined response by the light rail guard and the passengers prevented the injury of other innocent people”.
An attempted stabbing attack was foiled later that day when a Palestinian attacker lunged at police near Damascus Gate.
Israeli police officers shot and disarmed the attacker, a 37-year-old man from East Jerusalem. He later died of his wounds in Hadassah Mount Scopus Hospital. The police officers were unharmed.