All this was played fast by Nepomniachtchi. He must have studied this line during his world championship match preparation.
1. d2d4  1... g8f6  2. g1f3  2... d7d5  3. c2c4  3... e7e6  4. b1c3  4... c7c5  5. e2e3  5... b8c6  6. c4d5  6... e6d5  7. f1b5  7... c5d4  8. f3d4  8... c8d7  9. e1g1  9... f8d6  10. d4f3  10... d7e6  11. b2b3  11... a7a6 Caruana probably didn't expect this move, since he had to take some time to think after seeing it. 12. b5d3 