Harry Potter And The Half-Blood Prince scored the second biggest five-day domestic debut of 2009 as an estimated $159.7m dominated the charts and confirmed the film’s opening day promise.

While Universal/MRC’s Bruno took a big tumble on the catwalk, Warner Bros’ sixth episode in its lucrative family franchise was the belle of the ball, flying high after securing the second biggest five-day launch of the year-to-date after the $201m produced by Transformers: Revenge of The Fallen in June.

Combined with the record $237m international debut the film has already amassed $396.7m worldwide in the biggest global launch ever. However, the big numbers were not enough to prevent overall domestic box office sliding 39% against the same period last year, when The Dark Knight launched on $158.4m over the three-day weekend.

Nonetheless Warner Bros executives will be delighted with the weekend result as they also celebrated crossing $1bn in domestic grosses for the ninth consecutive year and the tenth out of the last 11 years.

Harry and his Hogwarts chums have already surpassed the $139.7m that its predecessor Harry Potter And The Order Of The Phoenix grossed in its first five days.

Furthermore domestic distribution chief Dan Fellman intimated that Half-Blood Prince would become the first film in the series since 2001’s The Sorcerer’s Stone to cross $300m and was expected to cross $200m by mid to late next week.

In terms of its three-day figure, Half-Blood Prince’s $79.5m haul ranks marginally ahead of Order Of The Phoenix’s $77.1m from two years ago. The latter went on to gross $292m domestically and $938.2m worldwide.

Bruno fell 72.7% in its second weekend, a major setback for the dethroned MRC/Universal release that slipped to fourth place on $8.4m for $49.6m.

In further good news for Warner Bros, The Hangover has overhauled Beverly HIlls Cop’s 24-year record to become the biggest R-rated comedy of all time on $235.9m. Legendary Pictures partnered with Warner Bros on the comedy, which climbed one place to sixth.

Elsewhere, Fox’s Ice Age: Dawn Of The Dinosaurs held on to second place in its third weekend on $17.7m for a little over $152m, while Paramount/DreamWorks’ Transformers 2 ranks third after four and is currently the biggest domestic hit of the year so far on $363.9m.

Fox Searchlight released the romantic comedy 500 Days Of Summerstarring Zooey Deschanel and Joseph Gordon-Levitt in 12th place on $838,000 from 27 theatres. Summit’s war film The Hurt Lockerclimbed four places to 13th in its fourth weekend after expanding by 34 theatres to 94 and adding $764,000 to $2.2m.

Next weekend’s wide releases are: Buena Vista’s family adventure G-Force; Warner Bros’ horror tale The Orphan; and Sony’s romantic comedy The Ugly Truth.

Estimated Top 10 North America July 17-19, 2009 Film (Dist)/Int’l dist/Est wkd gross/Est total to date:

1 (-) Harry Potter And The Half-Blood Prince (Warner Bros) WBPI $79.5m $159.7m

2 (2) Ice Age: Dawn Of The Dinosaurs (Fox) Fox Int’l $17.7m $152m

3 (3) Transformers: Revenge Of The Fallen (Paramount/DreamWorks) PPI $13.8m $363.9m

4 (1) Bruno (MRC/Universal) UPI/SPRI/Mandate Int’l $8.4m $49.6m

5 (6) The Hangover (Warner Bros/Legendary) WBPI $8.3m $235.9m

6 (5) The Proposal (Buena Vista) WDSMPI $8.3m $128.1m

7 (4) Public Enemies (Universal/Relativity) UPI $7.6m $79.5m

8 (8) Up (Buena Vista/Pixar) WDSMPI $3.1m $279.6m

9 (9) My Sister’s Keeper(Warner Bros) NLI $2.8m $41.5m

10 (7)I Love You, Beth Cooper (Fox) Fox Int’l $2.7m $10.3m