The headline is about an American basketball player, Jeremy Lin, who is all the rage these days. The problem is that the headline would be rather upsetting reading for a BrE-speaking Lin fan. In BrE to top oneself is a colloquial way of saying 'to kill oneself'. But it was the AmE meaning 'to surpass oneself/one's previous achievements' that was clearly intended by the New York Times.
It's not necessarily the case that the "AmE" meaning is entirely AmE here--the 'surpass' meaning of top is general English. But with the reflexive pronoun, it's not the first meaning to come to mind in BrE. The 'suicide' meaning comes from a more general use of top meaning 'to kill'--which originally referred to killing by hanging, but which is used more generally now for execution/killing in BrE, but not AmE.
And while I'm talking about topping... The OED mentions to top and tail [a baby], which I only learned as a new mother in the UK. Not having been a new mother in the US, I can't swear this is BrE only, but corpus and internet evidence seems to suggest so. If you know top and tail meaning to cut the ends off (of) vegetables (e.g. green beans) (which seems to be used a bit in AmE, but not as much as in BrE), then the image of topping and tailing one's infant child is a horrid thought. But what it means is to wash only the head and bottom of the child, as newborn skin doesn't need or appreciate lots of unnecessary washing.
And for another verbal use of top in BrE, see this old post on top up.
Oh, and P.S.
I'm sorry not to have been blogging much lately, in spite of my grand intentions at the start of the year. But here's a bit of what I've done instead: