She's dating a world-class boxer ... but Hayden Panettiere appears to be the one in peak physical condition.
Hard-bodied Hayden hit the beach in Malibu this weekend ... with what appears to be a Hello Kitty bikini and ... zero percent body fat.
Hayden Panettiere's Bikini ... Hello Kitty!!!
6/7/2010 5:03 AM PDT BY TMZ STAFF
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