I’ve had a front-row seat on a fascinating drama unfolding behind the international grosses for Universal’s Fast Five and Paramount’s distribution of Marvel /Disney’s Thor over the past 10 days. This weekend they went head to head in more than a dozen countries. The feud started because of Paramount’s decision to move onto Fast Five‘s Easter weekend Down Under. That created ill will, so Universal has been crowing about how much its street racing fivequel has been beating the Norse god pic overseas. Now Thor insiders are nervous that the lopsided victory of Fast Five internationally will hurt the Disney/Marvel’s domestic box office when it opens in the U.S. and Canada this coming Friday. Rarely have I seen studios bicker back and forth about box office as intensely as during this matchup. Especially when Paramount is only distributing Thor for its standard fee from Marvel. But it’s all about market share and just plain pride. Universal has been hit starved in the live action arena for so long that it’s releasing foreign numbers almost hour by hour, to the great consternation of Paramount which is pointing out that sequels always do better overseas. Paramount also is claiming that this may be Universal’s only really big hit of the summer. Strange thing to say, since Paramount is distributing foreign for DreamWorks/Universal’s Cowboys & Aliens. But, hey, all is fair in love and war and grosses, and I’m enjoying the heck out of this box office throwdown.

Universal preened about Fast Five results in Russia (where FF 68% ahead of Thor), Germany (FF 86% ahead of Thor), Spain (FF 30% ahead of Thor), Austria (FF 202% ahead of Thor), Switzerland (German-speaking area), Lithuania, Romania, Slovenia, UK, Australia, New Zealand, Turkey, and Korea. But Paramount boasted that Thor recorded the highest opening weekend gross at the international box office this year and had big No. 1 openings this weekend in the UK, Ireland, France, Korea, New Zealand, Mexico, and Italy.

Paramount said the Norse god “thundered to #1 in the international BO this weekend”, grossing $83M from 56 markets. Thor played at over 7,250 locations in all, and has now cumed $93M overseas including the one week earlier engagement in Australia. Fast Five opened first overseas 10 days ago and this weekend grossed a huge $45.3M at 3,211 dates in just 14 territories. That raised its early international tally to $81.4M. So now the worldwide total stands at a whopping $165M. The pic opened No. 1 in each of the 10 new markets. The openings are bigger than all the previous Fast franchise films. Rival studios tell me Fast Five is on track for a $300M foreign and $500M worldwide finish.

Fast Five has 49 territories still to open, including France, Italy, Brazil, and Mexico next weekend, and China and Israel May 12. Highlights include Russia which had a record breaking No. 1 opening with $11.5M at 712 dates for Universal’s biggest opening ever there and the biggest 4-day weekend opening in Russia this year. Germany opened No. 1 with the biggest opening this year. Spain had a record breaking weekend for Universal’s biggest opening weekend ever and Friday was Universal’s biggest opening day ever there. Turkey broke the record for Universal’s biggest opening day and Universal’s biggest opening weekend ever in that market.

Paramount bragged that Thor “stormed straight to #1″ in the UK & Ireland with a gross of $9M from 500 locales over five days. ”With previews it also exceeded the opening gross from Fast Five (with previews) in the UK last weekend. And #1 in Korea, Thor was 65% ahead of the opening of Fast Five in that market last weekend. Thor opens next Friday in the U.S. and Canada, with Finland, China, and Japan still to come.

Meanwhile, in its 4th weekend of international release, Twentieth Century Fox’s Rio from Blue Sky Studio continues to shake its tail feathers for $31.7m from 10,560 screens in 67 markets for a massive International cume-to-date of $263M, much of it because it’s hot, hot, hot in Latin America.

Editor-in-Chief Nikki Finke - tip her here.