Twentieth Century Fox’s bloodsucker parody “Vampires Suck” got a head start on the weekend’s crowded frame, posting a chart-topping Wednesday gross of $4 million at 2,978 locations.

Midweek launch marks a solid start for “Vampires,” which will expand to 3,233 engagements today as it competes with a slew of new entries this weekend.

Directed by the helming team of Jason Friedberg and Aaron Seltzer, “Vampires” pokes fun at the rampant vampire-themed phenomenon, led by the uber-popular “Twilight” series. With younger auds ready to return to school, Fox looked to entice moviegoers still on vacation during the midweek.

“(There’s) nothing wrong with having a good time to end the summer,” one studio insider said.

According to a Fox distribution exec, about 88% of college students have yet to go back to school, but that figure should drop to 53% next week. “Vampires” saw solid turnouts in the Midwest — including Chicago — along with favorable returns in New York and L.A.

Still, with many teenage fans turning out for opening day, rival studios predict the midweek debut could limit its Friday to Sunday weekend take.

“Vampires” beat out Lionsgate’s soph sesh holdover “The Expendables,” which totaled $3 million on Wednesday, followed by Sony pic “Eat Pray Love,” which grossed $2.9 million that day.

“Vampires” marks the fourth collaboration between helmers Friedberg and Seltzer; their 2006 “Date Movie” performed well with a $19.1 million opening (and a cume of $48.5 million).

The duo’s most recent effort, 2008’s “Disaster Movie,” lived up to its name, debuting with $5.8 million and finishing with $14.2 million.