ChessMexico, Rd. 4 : Aronian scores his first win in a game that started out slow, seemingly endless jockeying for position and a lot of saber rattling. I thought 24. f4 signaled the beginning of hostilities since it was a very committal move, but the following moves were jockeying moves again. Until, Aronian played 28. e5. See below:

Here, Leko moved 28...de5, giving up a piece for two pawns. Obviously, Leko pinned his hopes on these two connected pawns which Aronian blocked with his knight, for a while, as he sought to create a passed pawn on the queenside. Play continued 29. Rd7 ef4 30. Qe2 e5 31. Ne4 Be7 ( there was a threatened fork on d6 ) 32. c5 bc5 33. bc5 ( there's the newly minted passed pawn ) Bc6 34. Rdd1 Bb5 35. Qb2 Qa7 36. Bb5 ab5 ( Aronian seems to have strategized to reduce material ) 37. Bf2 Qa8 38. Nd6 ( more simplification ) See below:

Leko decided to cross the Rubicon and go for broke by playing 38... e4, planning to crash into Aronian's kingside for some counterplay. So, Aronian went on with 39. Ne8 ( threatening mate on g7 ) Re8 40. Nd4 ( now, Aronian was quality up after winning a piece for two of his pawns ) Bf6 41. c6 e3 42. Be1 f3 43. gf3 ( I think this capture took out the bite in this pawnroller ) Nf4 44. Bg3 Ne6 45. Qb4 1-0. I have wondered about 44...e2 and it could have gone 45. Bf4 ed1(Q)+ 46. Rd1 Bd4 47. Qd4 Qc6 and white is a bishop up but no longer has a passed C pawn. It would have still been a winning game for Aronian.