Stephen Strasburg was dominant for eight innings but gave up a game-tying, two-run homer to Donnie Murphy with two outs in the ninth before the Nationals answered with a run in the 13th for a 5-4 win over the Cubs at Wrigley Field on Thursday. Denard Span led off the 13th with a double, and pinch-hitter Chad Tracy scored him on a groundout with one out.