CHICAGO (AP) -- Stephen Strasburg and the Nationals were cruising along until it all fell apart. Then, a slow roller bailed them out.
Denard Span scored the go-ahead run on pinch-hitter Chad Tracy's grounder in the 13th inning, and the Nationals beat the Chicago Cubs 5-4 on Thursday after Strasburg blew a three-run lead in the ninth.
Span doubled leading off the 13th against Michael Bowden (1-3). He moved up on a sacrifice bunt by Steve Lombardozzi and came around on Tracy's roller to the first-base side of the mound.
''We got to do better than that. I mean, that gave me a heart attack,'' manager Davey Johnson said, smiling. ''It's a good thing we had a track star down on third base. But a win is a win.''
Craig Stammen (7-5) worked two innings and earned the victory. Drew Storen secured his third save in eight chances.
Storen deflected Dioner Navarro's liner toward Lombardozzi to start a game-ending double play after Anthony Rizzo reached on a throwing error by the second baseman with one out.
After a two-hour rain delay at the start, Strasburg was one out away from a complete game with a 4-1 lead before Chicago rallied to tie it.
Junior Lake had an RBI single, and Donnie Murphy hit a two-run homer to make it 4-4. Rafael Soriano gave up a double to Brian Bogusevic before Darwin Barney lined to left, sending the game to extra innings.
Before the rally, Strasburg and the Nationals were sailing along.
Ryan Zimmerman and Lombardozzi homered, and Strasburg added two hits, including an RBI single, as Washington built a 4-0 lead against Travis Wood.
Strasburg was aiming for his second shutout in three starts before Chicago's Brian Bogusevic homered leading off the eighth. When the Cubs struck again in the ninth, Chicago spoiled the ace's dominant outing.
''I've seen him pitch all the time, but I never got to face him,'' said Murphy, a 30-year-old journeyman with eight homers in 16 games since joining the Cubs about three weeks ago. ''Going in there and him K-ing me three times before getting the last hit was pretty cool.''
Strasburg gave up seven hits, struck out eight and walked two after the shortest start of his career. He was ejected in the second inning at Atlanta last week for throwing two consecutive pitches behind Andrelton Simmons' back.
Strasburg acknowledged he was tired toward the end of Thursday's game.
''If we get more consistent and I throw the same amount of innings, I feel like I get stronger, especially in the later innings,'' said Strasburg, who was surprised to bat in the ninth. ''But that 26-pitch debacle last game kind of set me back a little bit as far as stamina.''
He sure looked good for most of the day, though. Wood, meanwhile, settled down after allowing a solo homer to Zimmerman in the first and two runs in the second. But that drive by Lombardozzi leading off the seventh gnawed at him.
''That homer by Lombardozzi in the seventh kind of stings, especially the way we battled back and ended up putting up four there in the ninth. The game would have been over,'' said Wood, who allowed four runs and seven hits in 6 2-3 innings.
NOTES: The Nationals held SS Ian Desmond out of the lineup because of a back problem. His back tightened up during batting practice on Wednesday, and he stayed in until the fifth inning of that game, when he was replaced by Anthony Rendon as part of a double switch. ... Cubs OF Ryan Sweeney, on the 60-day DL because of a broken left rib, is scheduled to start a rehab assignment in the Rookie Arizona League on Saturday. 3B Luis Valbuena (strained muscle on right side) will head to Arizona to take batting practice from the minor league coaching staff. RHP Scott Baker, recovering from Tommy John surgery, is scheduled to start Friday for Class A Kane County. ... Cubs manager Dale Sveum said he doesn't envision SS Javier Baez being called up in September, although he has been impressed with his play. Baez is hitting a combined .286 with 33 homers and 100 RBIs for Class A Daytona and Double-A Tennessee. ... RHP Edwin Jackson (7-13, 4.89 ERA) starts Friday for the Cubs at San Diego, with RHP Edinson Volquez (9-10, 5.72) going for the Padres. Washington visits Kansas City, with LHP Gio Gonzalez (7-6, 3.38) starting for the Nationals and LHP Bruce Chen (5-1, 2.20) pitching for the Royals.