Answered April 26th, 2019

Lonzo Ball had 19p/11r/13a vs Milwaukee, becoming the youngest player in NBA history with a triple-double at 20 years, 15 days - beating LeBron's 2005 mark by 4 days. Markelle Fultz would break it just 5 months later.

Who is the youngest Lakers player with a triple-double in a game?
Interpreted as:
Who is the youngest Lakers player with a triple-double in a regular season game?