The Eagles, 5-1 and winners of four straight games are starting to play as a complete team.
"Our team chemistry is one of our biggest strengths," said Purdy coach Tommy Egan. "We are unselfish. Tonight, we passed the ball really well. We made the extra pass to give up a good shot to get a great shot."
Twice at the start of the second period the Eagles opened a 6-point or greater lead (14-8, 18-11) only to see Riley Jack hit a 3-pointer to pull the Cardinals closer.
Despite Jack's attempts to keep the score close, the Eagles used a 11-1 push to close out the first half with 29-18 edge. Alex Mareth keyed Purdy's rally to end the second quarter with 6 points.
Miller opened the third period with a quick 6-0 spurt to close the gap to 29-24 with six minutes remaining.
Purdy, after a timeout, responded with two baskets from Brent Cornman and a deuce from Keevin Walker to re-establish a 40-27 lead to end the third period.
Purdy wouldn't allow Miller to draw close in the final quarter hitting 14 of its 16 attempts from the charity stripe.
For the game, the Eagles finished 24 of 33 (72.7 percent) from the line.
"Hitting our free throws down the stretch was a big key (to victory) tonight," said Egan. "We still need to cut down on our turnovers and improve on rebounding on both ends of the floor. We are getting better."
Riley Jack led the Cardinals in scoring with 24 points including five 3-pointers. Jordan Jack added 10 points.
Scoring for Purdy: Cornman and Mareth, 14 points each; Cameron Terry, 11; Walker, 10; Glenn Scott, 6; Tyler Scott, 4; Austin Hancock, 3;
The Eagles will be in action on Dec. 18 against Diamond. Tipoff is set for 6 p.m.