With this strange-looking move Topalov clearly  indicates his intentions. What else can the knight do on f4, if not  sacrifice itself on e6?!
1. e2e4  1... c7c5  2. g1f3  2... d7d6  3. d2d4  3... c5d4  4. f3d4  4... g8f6  5. b1c3  5... a7a6  6. f2f3  6... e7e6  7. c1e3 An  interesting fact. The Najdorf was Topalov's bread and butter on the road  of the world championship title before switching to more quite lines,  whereas Vachier-Lagrave constantly uses the sharp Sicilian. 7... b7b5  8. d1d2  8... b8d7  9. g2g4  9... b5b4  10. c3e2  10... h7h6 