The Capitals were hosting the Kings, and facing a gut-wrenching loss as they battle for an Eastern Conference playoff spot. But with just under a minute to go, after blowing a pair of two-goal leads, rookie forward Evgeny Kuznetsov tied the game to force overtime.
Halfway into the extra period, the two Capitals were skating through center ice, apparently unaware of one another as they crossed paths. Hillen's helmet went into Ovechkin's chest and they both went down.
Ovechkin made it to his skates and played on, but Hillen, after remaining face-down on the ice several minutes as training personnel tended to him, was helped off the ice and did not return.
It was an extremely painful 5-4 shootout loss for host Washington. Ovechkin scored twice in the game's first 10 minutes (his league-leading 47th and 48th goals), and the team also lost star center Nicklas Backstrom to an upper-body injury.
Both Backstrom and Hillen we be evaluated on Wednesday.