Entering the round, Maxime Vachier-Lagrave, Leinier Dominguez, and Wesley So were tied for first, with Fabiano Caruana half a point behind. By the end of the round, for the first time in the tournament, there was a single leader: Vachier-Lagrave. He defeated Jeffery Xiong, while Dominguez and So drew their games to fall into a second place tie with Caruana, who defeated Shakhriyar Mamedyarov.
For MVL, it was his fourth win of the event, and he was somewhat fortunate. Xiong was doing fine on the black side of the Berlin endgame until he blundered with 18...hxg4??, blind to the danger on the h-file. Had he played 18...g6 he would have been better, especially against Vachier-Lagrave's intended continuation. If, if, if.
So could do a bit of what-iffing as well. He had a big advantage against Sam Shankland, of a sort one would normally expect him to convert to a win. Very uncharacteristically, he quickly let it slip away, and the game soon ended in a repetition.
Dominguez had nothing to feel bad about in his game, except his opponent's high-quality prep and play. Dominguez found a fascinating gambit idea as Black against the Queen's Gambit sideline chosen by Richard Rapport. He did everything right...but so did his opponent, who had apparently researched the idea as well. The result was a well-played draw.
Caruana's game with Mamedyarov was a very complicated affair, with both sides playing - justifiably! - for a win. Mamedyarov probably had the better chances, at least practically, with much more time on the clock and the option of a safe pawn-up ending for the taking (even if it was objectively drawn if Caruana reacted correctly). Instead, he used most of his time choosing an incredibly risky option, and when Caruana made the obvious rejoinder used half his remaining time and chose a very poor move. Mamedyarov fought a while longer, but even though Caruana's clock went down to three seconds at one point (scary, but not nearly as much as it would be were it not for the 30-second increment) he was unable to save the game.
Finally, the only game without first-place implications was the battle between the tailenders. Dariusz Swiercz got greedy on the black side of an Anti-Marshall against Peter Svidler, and paid the price.
With two rounds to go, there is still everything to play for, both for the tournament and the overall Grand Chess Tour standings. If MVL takes clear first in the tournament and So finishes no higher than fifth, the Frenchman will take the overall title and the $100,000 bonus. And since they play tomorrow, with Vachier-Lagrave having the white pieces, it's far from impossible that he could push So back into 4th - which would be a tie for fourth-fifth if Rapport wins his game. And there's still one more round after that, too, which will see So face off against Dominguez. And while neither Mamedyarov nor Caruana could take first or second in the GCT, they are battling for third. Mamedyarov had a big lead coming into the event, but now he's tied for 6th-8th while Caruana is in the running for first. Anything is possible in that race, too.
Anyway, here are the games, with my comments, and here are the pairings for both round 8 and round 9. It has been quite the tournament.
Round 8:
Round 9: