BOSTON – Maciej Lampe looked like a different player yesterday in his third summer-league outing. The 18-year-old 7-footer finished with 21 points in 31 minutes in yesterday’s triple-overtime 103-101 Knick victory over Dallas. He made 7 of his 8 free throws as he showed a dynamic inside-outside game.

“[The Knicks] told me you were the player we thought you were,” Lampe said. “This is how I play normally. The first game was just a joke.”

Lampe’s offensive display overshadowed his big gaffe when he failed to box out after a free throw late in the first overtime. With the Knicks leading 96-94, Tony Stanley, a 6-4 guard, snuck by Lampe to snare the missed free throw and laid it in, forcing a second OT.

*

First-rounder Mike Sweetney scored 20 points with 13 rebounds and 4 steals . . . Frank Williams led Knicks with 35 points . . . Reps for 7-6 Slavko Vranes (4 points) have all but settled Serbian contract buyout and is free to negotiate with the Knicks.