The winner
Until this weekend, the biggest UK opening of the year had belonged to Transformers: Revenge of the Fallen, which began its life in June with £8.35m. But the boy wizard has kicked dirt in the faces of Michael Bay's robots and trampled them into the ground: Harry Potter and the Half-Blood Prince debuted with £11.93m plus £7.85m from previews on Wednesday and Thursday. The £19.75m five-day total is bigger than the opening of the previous entry in the film franchise, but then Harry Potter and the Order of the Phoenix's debut weekend figure of £16.49m included just one day's worth of previews. Comparing just the Friday-to-Sunday takings, Order of the Phoenix in fact opened bigger than Half-Blood Prince: £13m, against the new film's £11.93m.

Nevertheless, in just five days, The Half-Blood Prince has already overtaken several of this summer's blockbusters, such as Night at the Museum 2, Wolverine, Angels & Demons and Terminator Salvation. This time next week it will also have punched past Ice Age: Dawn of the Dinosaurs, Star Trek and Transformers to become the biggest hit of the season. The success of Half-Blood Prince helped the top 15 films overall to post the biggest combined total (£27.75m) of any weekend from the last 52. The market is 83% up on the corresponding weekend from 2008, when The Dark Knight and WALL-E battled for the top spot.

The fast faller
Having opened above £5m, Bruno was always going to struggle to maintain that pace. But the comedy's 54% drop this weekend will be seen as a slight disappointment, especially when compared with Borat's very modest 15% fall on the second weekend of its run, back in October 2006. Ten days into its run, Bruno has now grossed £10.36m; at the same point, Borat had taken £14.19m. Backers Universal will be hoping that the 15-certificate version of Bruno, which opens on Friday, will re-energise its film at the nation's multiplexes.

The big loser
With a 78% plunge this weekend, Year One is the fastest faller in the market. Having opened in late June with £978,000, the comedy has seen its weekend takings dwindle to a paltry £53,000, and its screen average decline to £316. Year One will now presumably shed the bulk of its 168 remaining screens and disappear from most parts of the country.

The indie hit
Summer 2009 has been light on alternatives to blockbusters, but Moon marks a rare appearance in the top 10 for an indie flick. The British sci-fi picture, which was acquired by Sony Pictures Classics at the Sundance film festival earlier this year, began its run with an encouraging £158,000 from 57 cinemas. The key to the film's success is good reviews, which appear to have offset lead actor Sam Rockwell's patchy track record at the UK box office: the last film to feature him as lead actor, Choke, opened with £55,000 from 45 screens.

The future
The summer has more or less shot its load of blockbuster event pictures, meaning there is little arriving imminently that is capable of challenging Harry Potter for supremacy. However, Disney will be expecting big things of The Proposal, opening tomorrow. The romantic comedy has already become Sandra Bullock's biggest ever hit in the US, overtaking Speed, and the market has been starved of romcoms throughout the summer period. The arthouse sector will take a keen interest in the success or otherwise of Lars von Trier's Antichrist. Can controversy and a DIY female circumcision be converted into bums on seats? Watch this space.

UK top 10, 17-19 July
1. Harry Potter and the Half-Blood Prince, 584 sites, £19,784,924. (New)
2. Ice Age: Dawn of the Dinosaurs, 503 sites, £2,849,981. Total: £20,283,183
3. Bruno, 457 sites, £2,301,432. Total: £10,357,495
4. The Hangover, 359 sites, £881,514. Total: £18,142,083
5. Transformers: Revenge of the Fallen, 405 sites, £678,743. Total: £24,919,977
6. Public Enemies, 360 sites, £470,651. Total: £5,728,410
7. My Sister's Keeper, 311 sites, £378,680. Total: £4,955,541
8. Moon, 57 sites, £157,867. (New)
9. Year One, 168 sites, £53,033. Total: £2,776,236
10. Night at the Museum 2, 203 sites, £49,570. Total: £19,560,553

How the other openers did
Frozen River, 7 screens, £18,594
The Informers, 4 screens, £6,149
Wide Open Spaces, 9 screens, £5,924
Burma VJ, 6 screens, £4,626 (plus £26,896 in previews from 39 screens)
Kisses, 6 screens, £3,310