The domestic box office saw a nice change of pace this Presidents Day weekend, with solid (but not stellar) three-day perfs from its top players, led by Warner Bros.’ Liam Neeson thriller “Unknown,” which debuted with an estimated $21.8 million through Sunday from 3,043 locations.

And while moviegoers spread the wealth among the frame’s high-ranking pics, the holiday weekend lacked its usual breakout hit as new entries played mostly to one demographic.

“Unknown,” which played better than Warners’ mid- to high-teens pre-weekend projection, skewed overwhelmingly toward an over 25 crowd (84%), with auds older than 50 contributing 54%. DreamWorks’ “I Am Number Four,” with Disney distribbing, also played more to adults (pic lacked its expected teenage femme aud) and came in neck-and-neck with the Mouse House’s 3D toon “Gnomeo and Juliet,” benefiting as the frame’s only family film.

Disney is estimating “Four,” with $19.5 million for the three days at 3,154 playdates, to have debuted slightly above “Gnomeo,” which took in an estimated three-day gross of $19.4 million at 3,014.

The Mouse’s horses could swap, however, since most other studios have “Gnomeo” beating “Four” with grosses through Sunday. On Monday, when studios release four-day estimates (some already have), bizzers expect to see “Gnomeo” gain considerable ground as families tend to drive the holiday box office.

The frame’s other wide release, 20th Century Fox’s “Big Mommas: Like Father, Like Son,” debuted at No. 5 for the three days, estimating $17 million with Fox predicting a four-day take of $20 million from 2,821 locations.

Meanwhile, Sony’s soph sesh player “Just Go With It” held in nicely, down 40% for a three-day take of $18.2 million and a cume of $60.8 million. That was more than enough to keep it above Paramount’s “Justin Bieber: Never Say Never” – also in its second frame – which fell 53% with an estimated $13.6 million through Sunday. Similar music concert pic “Hannah Montana/Miley Cyrus: Best of Both Worlds Concert Tour” dropped more (67%) in its second outing.

The Weinstein Co.’s boffo Oscar-nommed “The King’s Speech,” was off just 9% in its 13th week. TWC is estimating the film to have grossed $6.6 million for three days, lifting its domestic cume to $103.3 million, above Fox Searchlight’s “Black Swan” with a total $101.5 million as of Sunday.