The first game to finish, Gustafsson-Naiditsch, may have featured the event's lowest-rated players, but it was surely the game of the day. Gustafsson introduced a new move in the Vienna Variation of the QGD (16.f4), and while I think Black can neutralize it with 17...Rac8!, it's quite easy to prefer Naiditsch's 16...Rab8 OTB. It's natural and logical, but it loses, and Gustafsson crushed him quickly.
The second completed game was the only draw of the day. Nepomniachtchi had some advantage on the White side of a Closed Ruy, but after missing some opportunities Mamedyarov managed to equalize and draw.
Shortly thereafter, Kramnik finished his crushing win over van Wely in a Colle (Zukertort version)/Slav hybrid. Kramnik made it look easy: Ne5, Qf3-h3, f4, etc...but it's the "etc." that took the skill. One remarkable feature of the game was that despite Kramnik's kingside buildup, he simultaneously managed to lure all of his opponent's pieces to the queenside, with predictable results.
Finally, Leko defeated Ivanchuk in his best style. Step 1: press strategic advantages. Step 2: when the opponent lashes out to relieve the pressure, exploit this tactically. Step 3: calmly cash in the winnings collected in step 2. The game went 57 moves, but it had been decided from move 25.
Standings after Round 2:
1-3. Kramnik, Leko, Gustafsson 1.5
4-5. Nepomniachtchi, Mamedyarov 1
6-8. van Wely, Ivanchuk, Naiditsch .5
Round 3 Pairings: (On Tuesday; tomorrow is a rest day)
Naiditsch - Kramnik
Mamedyarov - Gustafsson
Ivanchuk - Nepomniachtchi
van Wely - Leko
The round 2 games, with my comments, are here.