Karlsson scored twice in the third period to send the game to overtime in Sunday's 4-3 victory over Colorado.
Karlsson reached the 30-goal mark with his two-goal third period, which included a power-play tally. The only other time Karlsson has reached that threshold was his 43-goal campaign in the Golden Knights' inaugural season in 2017-18. He has been hot down the stretch, with six goals and 13 points over the last 10 games.