My physical condition is roughly the same (maybe a bit better in certain respects, but maybe worse in another), so I'm afraid I'm going to offer an even more cursory report than I did for the last round. So let's get on with it while I can.
Vladimir Kramnik entered the round half a point ahead of Magnus Carlsen, and scheduled for White while Carlsen was due Black (not against each other). Nevertheless, I felt that today's pairings presented a better opportunity for Carlsen, and that's just how things turned out. Kramnik pressed hard against his long-time friend (or at least very friendly colleague) Boris Gelfand and seemed close to a win at times, but Gelfand's resourceful counterattacking defense with his rooks enabled him to save the game. (For theory-watchers, Kramnik's 5.e3 was a fascinating new move (at least new to this level), and Gelfand was very complimentary about the idea and in his respect for Kramnik's ability to find new opening concepts. Gelfand offered a remark to the effect that in recent years, Kramnik may have come up with more new ideas than the rest of us combined.
I'm sure the compliment was appreciated, but the bottom line is that Kramnik didn't get what he needed today, and now his fate is out of his hands. Carlsen had virtually nothing against Teimour Radjabov for a long time, but (especially) given Radjabov's last-place status and his self-admitted lack of confidence, Carlsen was entirely justified in playing on and hoping something would turn up. As it so often happens with Carlsen's opponents, something did, and after 89 moves and almost seven hours of play, Carlsen had pulled off the win.
This leaves Carlsen and Kramnik tied for first, but due to the unfortunate decision to use tiebreaks rather than a playoff, and the further (to my mind unfortunate) fact that the tiebreak that will settle things in this case is "most wins" (why not "fewest losses?" But let me emphasize that I think both are lousy - use a playoff!), it means that if Carlsen defeats Peter Svidler tomorrow (Carlsen will have the white pieces), he wins the event no matter what Kramnik does. Kramnik will have Black against Vassily Ivanchuk, which makes for a pretty random situation. Ivanchuk has had a lot of disasters in this tournament, many of them self-inflicted, but he has also won his last two games with White - including round 12 against Carlsen.
For completeness' sake: Svidler defeated Ivanchuk in good style, while Alexander Grischuk and Levon Aronian drew, resulting in the latter's mathematical elimination from the race for first.
Standings After Round 13:
Last Round Pairings:
Tournament website here.