Chesterfield midfielder Lowry diverted Darren Anderton's looping header into the roof of his own net as he tried to clear eight minutes from time.
Lloyd Kerry fired the Spireites into a first-half lead after Bournemouth keeper Shwan Jalal had spilt Jamie Ward's curling effort.
Bournemouth began comfortably in testing conditions, keeping possession but with little forward penetration to suggest an opener.
Chesterfield on the other hand were content with getting men behind the ball and aiming to counter-attack on the break.
Jalal almost gifted them an opener on 22 minutes when he came to collect a Ward corner only to drop the ball at the feet of Dan Gray, whose shot was blocked on the line by Warren Cummings.
The Bournemouth keeper's uncomfortable afternoon increased 12 minutes later when the lively Ward wriggled free of his markers and aimed for the far corner, before Jalal parried straight to Kerry who tapped in his second of the season.
The first half was turning into a real defensive horror show for the home side as Jason Pearce nearly gifted Chesterfield a second, passing straight to Ward who in turn released strike partner Jack Lester, but this time Jalal saved.
The second half continued in a similar vein with Bournemouth enjoying more and more possession, but struggling to break down a resolute Chesterfield backline well marshalled by captain Robert Page.
Michael Rankine's effort ten minutes after the break was heading for goal only for the former Wales International to divert its path away for a corner.
Substitute Brett Pitman nearly then squeezed an equaliser as he attempted an overhead kick two yards out but the ball rolled inches wide.
Just as they began to run out of ideas in the final third Chesterfield struggled to clear and the experienced head of Anderton proved decisive with a little help from Lowry.