Working its magic on the box office this weekend, HARRY POTTER AND THE CHAMBER OF SECRETS claimed the third highest grossing opening weekend ever, after its predecessor HARRY POTTER AND THE SORCERER'S STONE ($90.3M) and this summer's super SPIDER-MAN ($114.8M). Not surprisingly, CHAMBER, with primary visual effects by ILM, was the number one film this weekend, earning $87.6M. The wizards of Hogwart's knocked the rappers of Detroit down to second, as last week's number one film 8 MILE took in $21.7M for a two-week total of $54.4M. THE SANTA CLAUSE 2, with visual effects by Tippett Studios and GVFX, maintained well in its third week, slipping one spot to third with $15.1M for a total gross of $82.5M. THE RING, with visual effects by Method Studios, Rhythm & Hues, Asylum and Tippett Studios, continues to thrill audiences. Crossing the $100M mark this weekend, the film scared up $11M for a cume of $101.1M and fourth place. Action-comedy I SPY, with visual effects by Sony Pictures Imageworks, dropped to seventh with $4M for an unspectacular three-week take of $30.9M. GHOST SHIP, with visual effects by Photon VFX, sailed out of the top ten dropping all the way to fourteenth place with $1.1M for $28.3M. Putting EPISODE II on the big screen seems to be paying off. Playing on just 58 screens, ATTACK OF THE CLONES THE IMAX EXPERIENCE brought in just under $1M in its third weekend out, bringing the total to $4.8M. Box office information obtained from yahoo.com and boxofficemojo.com.