This past weekend, "Swimfan" dove into theaters and swam away with the top spot, according to studio estimates released Sunday.

Reportedly made for less than $10 million, the high-school-love-affair-gone-bad thriller took in $12.4 million in its opening weekend. (Click for photos from the movie.)

Starring Jesse Bradford ("Clockstoppers"), Shiri Appleby (TV's "Roswell") and Erika Christensen ("Traffic"), "Swimfan" tells the tale of a promising swimmer whose career is nearly derailed when a one-night stand turns all "Fatal Attraction" on him and his sweet, innocent girlfriend (see " 'Swimfan' Carries On Proud Tradition Of Teen Stalker Movies").

While "Swimfan"'s opening is impressive, it's the second-lowest tally for a #1 film since "Black Hawk Down" made $11.1 million in February.

Another low-budget hit, the independently produced "My Big Fat Greek Wedding," held on to the #2 spot with $10.6 million. "My Big Fat Greek Wedding" has been plugging along since April, thanks to word-of-mouth, strong reviews and the inclusion of 'NSYNC's Joey Fatone in a small role (see " 'Signs' Tops Again, But Fatone's Movie Earns Big"). Made for a reported $5 million, "My Big Fat Greek Wedding" is well on its way to grossing $100 million.

"City by the Sea," the weekend's other widely released new film, debuted at #3 with $9.1 million. Starring Robert DeNiro and James Franco ("Spider-Man"), it's the story of a cop who's desperately trying to clear his son of murder.

The rest of the top 10 includes "Signs" at #4 with $8 million for an overall total of $205.8 million, making it the fourth movie this year to earn over $200 million; Vin Diesel's "XXX" at #5 with $5.5 million for $131 million overall; "Spy Kids 2" at #6 with $3 million, $73.9 million overall; "Austin Powers in Goldmember" at #7 with $2.8 million, for a $207.1 million total that has now surpassed each of the previous installments in the spy-spoof franchise; "Fear Dot Com" at #8 with $2.4 million, $10.5 million overall; the new double-header, double-feature of "Spider-Man" and "Men in Black II" at #9 with $2 million; and surf-chick flick "Blue Crush" at #10 with $1.8 million for $37.2 million overall.

This weekend's new entries will include Tom Green and Jason Lee's "Stealing Harvard" and Ice Cube and Eve's "Barbershop," while "The Transporter" has been bumped from Friday to a later date.