1.Nf3 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.Qa4+ Nc6 It seems funny to say, but the position proceeds here in a pretty logical way straight to a king and pawn ending.
6.Ne5 Qd6 [6...Ndb4 is the usual move, but it doesn't score so brilliantly.]
7.Nxc6 Qxc6 8.Qxc6+ bxc6 9.g3 Bg7 10.Bg2 Rb8 11.b3 0-0 12.Bb2 Nxc3 13.Bxc3 Bxc3 14.dxc3 c5 All pretty logical so far. Now White grabs the d-file...
15.0-0-0 Rb6 and Black prepares to contest it as well.
16.c4 Fixing Black's pawn on c5.
16...Rd6 17.Rd5 What is Black to do about the c-pawn? Use tactics, of course.
17...Bb7 18.Rxd6 Bxg2 19.Rdd1 Bxh1 20.Rxh1 Rd8 Otherwise White seizes the d-file and gains a big advantage.
21.Rd1 But isn't this a problem?
21...Rxd1+ 22.Kxd1 Apparently not. Howell has either calculated or prepared this ending at home, and determined that Black holds it.
22...Kf8 23.Kd2 Ke8 24.Ke3 Kd7 25.g4 f6 26.Ke4 Ke6 27.h3 f5+ 28.Kf4 Kf6 29.g5+ Ke6 30.e4 fxe4 31.Kxe4 Kd6 32.f4 e6 33.h4 a6 34.a3 a5 35.Kf3 e5 36.Ke4 exf4 37.Kxf4 Ke6 38.Ke4 Kd6 39.Kf4 Ke6 40.Ke4 Thanks to the pawn on g6, there's no way for White to zugzwang his way in. 1/2-1/2