The Dark Knight clung on to the number one spot at the North American box-office for the fourth consecutive weekend and edged out Sony's stoner comedy Pineapple Express thanks to an estimated $26m haul that boosted the film to within touching distance of Star Wars' second spot in the all-time pantheon.

The Batman saga currently stands at $441.5m (as of estimates Aug 10) and should have little trouble overtaking Star Wars' $460m mark to sit behind Titanic as the second biggest grossing release in North American history in terms of unadjusted final grosses.

Pineapple Express launched on Wednesday and grossed $22.4m over three days and $40.8m over five. Sony's strategy backfired as the distributor launched the film mid-week to draw the school crowd during summer vacation and avoid clashing with the Olympic Games. Had the distributor opted for the traditional three-day launch the new arrival would have dethroned The Dark Knight over the three-day weekend.

Seth Rogen, James Franco and the fast-rising Danny McBride star in the action caper about a process server and his drug dealer who get involved with gangsters and a crooked cop. Judd Apatow produced and David Gordon Green directed.

Universal's The Mummy: Tomb Of The Dragon Emperor fell to third place in its second weekend on $16.1m for $70.7m, while Warner Bros' chick flick The Sisterhood of The Traveling Pants 2 ranks fourth following a Wednesday launch that generated $10.8m over three and $$19.7m over five days.

America Ferrera, Blake Lively, Amber Tamblyn and Alexis Bledel and star in the ongoing tale of a group of girlfriends.

Universal's hit musical adaptation Mamma Mia! ranks sixth and crossed $100m in its fourth weekend thanks to an $8.1m haul that raised the tally to $104m. Swing Vote, released in North America through Buena Vista, tumbled three places to ninth in its second weekend and stands at $1m.

Paramount Vantage's Sundance pick-up American Teen added $137,337 from 76 sites in its third weekend for $465,496 and is set to expand next weekend.

Lakeshore Entertainment's drama Elegy starring Penelope Cruz and Ben Kingsley, released through Samuel Goldwyn Films, launched on $102,441 from six screens for what Lakeshore sources claimed was the highest per-screen average of the weekend on $17,074.

The drama opened in New York, Los Angeles, San Francisco and Seattle venues and reportedly drew a 60% female audience that leaned towards the over-40 demographic. Goldwyn plans to expand into the top 25 markets and 100 screens on August 22.

Music Box Films' French thriller Tell No One added $374,667 for $2.9m.

Palm Pictures documentary Patti Smith: Dream Of Life added $8,080 on its single screen and stands at $14,228.

Latest figures put Paramount's Indiana Jones And The Kingdom Of The Crystal Skull has amassed $314,746,000 while Marvel Studios' Iron Man stands at $316.4m through Paramount.

Next weekend's wide releases are: Fox's horror title Mirrors starring Kiefer Sutherland; DreamWorks/Paramount's all-star comedy Tropic Thunder with Ben Stiller, Jack Black and Robert Downey Jr; Summit Entertainment's 3D animated story Fly Me To The Moon; Warner Bros' animated Star Wars: The Clone Wars; and MGM's Woody Allen comedy Vicky Cristina Barcelona featuring the talents of Javier Bardem, Scarlett Johansson, Rebecca Hall and Penelope Cruz.

Estimated Top 10 North America Aug 8-10, 2008
Film (Dist)/Int'l dist/Est wkd gross/Est total to date

1 (1) The Dark Knight (Warner Bros) WBPI $26m $441.5m
2 (-) Pineapple Express (Sony) SPRI $22.4m $40.5m
3 (2) The Mummy: Tomb Of The Dragon Emperor (Universal) UPI $16.1m $70.7m
4 (-) The Sisterhood Of The Traveling Pants 2 (Warner Bros) WBPI $10.8m $19.7m
5 (3) Step Brothers (Sony) SPRI $8.9m $80.9m
6 (4) Mamma Mia! (Universal) UPI $8.1m $104m
7 (5) Journey To The Centre Of The Earth (New Line) NLI $4.9m $81.8m
8 (7) Hancock (Sony) SPRI $3.3m $221.7m
9 (6) Swing Vote (Buena Vista) Kathy Morgan Int'l $3.1m $12m
10 (8) Wall-E (Buena Vista) WDSMPI $3m $210.1m