The winner: Aquaman

Warner Bros proclaimed Aquaman “king of the box office as well as the seven seas”, as its oceanic superhero ended the two-week reign of Ralph Breaks the Internet at the top of the UK box office, taking £5.23m, including previews.

However, Aquaman delivered only the 16th-biggest opening of 2018; strip out the previews and it achieved £3.82m. Excluding previews from the totals for all films, Aquaman delivered the year’s 19th-biggest debut. For comparison with other DC Films titles, Justice League began in November 2017 with £7.26m (no previews), while, five months earlier, Wonder Woman kicked off with £4.96m (£6.18m including previews). Globally, Aquaman stands at a decent $266m, and with North America yet to open.

The runner-up: Spider-Man: Into the Spider-Verse

With £2.28m including previews, Spider-Man: Into the Spider-Verse lands in second place. However, that number is inflated by significant previews – strip them out and the superhero animation achieved £1.24m.

In addition to Spider-Verse and Ralph Breaks the Internet, the third animation in the Top 5 is The Grinch. Its festive hook meant it saw only a modest decline, down just 13%, and it now stands at a handy £21.7m. Audiences will be aiming to catch this one in the runup to Christmas Day, rather than afterwards. Ralph and Spider-Verse should enjoy longer playability into January.

The flop: Mortal Engines

Mortal Engines landed in fifth place, with £1.27m. That sounds like a respectable number, but previews did the heavy lifting. For the weekend period, the Peter Jackson-produced steampunk adventure grossed a weedy £311,000 – which would put it in eighth place.

The film is based on a book series by Philip Reeve, and it was always questionable how meaningful this source material was to UK audiences. With a relatively unstarry cast, Jackson remained the film’s most marketable asset. The pricey production has grossed $42m worldwide so far and looks likely to become a big loss maker for its backers.

The documentary hit: Free Solo

Landing inside the Top 10 is Free Solo, which documents an attempt by climber Alex Honnold to scale the sheer rock face of El Capitan in California’s Yosemite National Park without ropes or safety gear. The film enjoyed a Q&A screening on Tuesday last week, which, together with a previous festival preview, put Free Solo at a healthy £251,000 even before its official release. It grossed £136,000 from 57 cinemas at the weekend, pushing the tally to £387,000.

The film is a potential game changer for documentary specialist Dogwoof. Until this year, the UK distributor’s biggest hit was Dancer, with £265,000. Dogwoof has just beaten that record with Three Identical Strangers, which is at £277,000. Free Solo should push into high six figures, and possibly £1m, depending on the word-of-mouth it earns.

The market

Given that the big new release this time last year was Star Wars: The Last Jedi, it’s no surprise to see the market down 52% overall. Mary Poppins Returns – likely to be this month’s highest-grossing film – arrives on Friday, a week later than The Last Jedi did a year ago. Given that virtually all cinemas are closed on Christmas Day, the musical sequel will only contribute 10 days of takings to the 2018 tally.

Cinema admissions in 2018 look well-placed to overtake the modern era’s high point of 2002 when 175.9m tickets were sold, and if this happens it would be the highest tally since 1971. Reaching the target will hinge on how well Mary Poppins Returns performs and how quickly it reaches its audience. Also contributing to the last-gasp effort are Transformers spinoff prequel Bumblebee and Will Ferrell and John C Reilly comedy Holmes & Watson, which both open on Boxing Day.

Top 10 films, 14-16 December

1. Aquaman, £5,230,285 from 604 sites (new)

2. Spider-Man: Into the Spider-Verse, £2,279,995 from 567 sites (new)

3. The Grinch, £1,747,936 from 637 sites. Total: £21,686,463 (six weeks)

4. Ralph Breaks the Internet, £1,402,006 from 613 sites. Total: £9,324,458 (three weeks)

5. Mortal Engines, £1,269,441 from 398 sites (new)

6. Creed II, £749,740 from 498 sites. Total: £7,414,211 (three weeks)

7. Fantastic Beasts: The Crimes of Grindelwald, £700,808 from 545 sites. Total: £30,541,674 (five weeks)

8. Bohemian Rhapsody, £537,344 from 530 sites. Total: £45,147,461 (eight weeks)

9. Free Solo, £387,402 from 57 sites (new)

10. La Traviata – Met Opera, £274,847 from 204 sites (new)

Other openers

CBeebies Christmas Show: Thumbelina, £195,580 from 376 sites

It’s a Wonderful Life (4K restoration), £114,865 from 44 sites

Odiyan, £44,479 from 56 sites

The House That Jack Built, £32,131 from 25 sites

Lizzie, £24,715 from 30 sites

Milosc jest wszystkim, £22,651 from 79 sites

Bhajjo Veero Ve, £8,808 from 10 sites

An Elephant Sitting Still, £5,596 from four sites

Sampiyon, £1,755 from three sites

Keepers of the Flame, £1,083 from three sites

Khrustalyov, My Car! (4K restoration), £884 from three sites

• Thanks to Comscore. All figures relate to takings in UK and Ireland cinemas.