Police arrested a 29-year-old man after he allegedly stabbed a 17-year-old boy at Beretania Community Park in Kalihi.
At about 9:30 p.m. Wednesday, police said the suspect stabbed the teen and caused a non-life threatening injury to a 20-year-old man before he fled.
One of the victims chased the suspect and detained him until police arrived.
Police said the suspect and victims are strangers.
Emergency Medical Services transported the teen, who was stabbed in the upper back, to a trauma center in serious condition.
Police arrested the suspect on suspicion of two counts of second-degree assault.