Adam Sandler and Jennifer Aniston are America's box-office sweethearts, but Justin Bieber is the valentine for teens.

The Valentine's Day weekend was a close one as Adam and Jennifer's romantic comedy Just Go With It, debuted with 31 million dollars, according to studio estimates.

That was just ahead of the concert documentary Justin Bieber: Never Say Never, which opened a close second with 30.3 million.

Sony's Just Go With It and Paramount's Never Say Never were close enough that the rankings could change when studios release final numbers.

The teen pop idol's flick exceeded industry expectations and nearly matched the 31.1 million dollar opening of 2008's Hannah Montana & Miley Cyrus: Best of Both Worlds Concert, the record-holder for music-documentary debuts.

Another love story, Disney's animated adventure Gnomeo & Juliet, opened solidly at number three with 25.5 million dollars. The movie features the voices of Emily Blunt and James McAvoy in a twist on Romeo and Juliet told with garden gnomes.

The weekend's other new wide release, Focus Features' ancient Roman saga The Eagle, was number five with 8.6 million. The film stars Channing Tatum and Jamie Bell on a quest into the wilds of 2nd century Scotland.

Though Hollywood generally did strong business, revenues were still down compared to the previous year's for the 14th weekend in a row.