WASHINGTON (AP) -- Johnny Cueto was having a season of such historic proportions that it was totally unrealistic to expect him to keep up the pace.
Still, it was jarring to see him pestered by a disruptive leadoff hitter, to see him plunk two batters in the same inning, to see him yield hit after hit as if he were an ordinary pitcher having a bad day.
Cueto returned to mortality Tuesday night when the Reds lost 9-4 to the Washington Nationals.
"They played really well. And you know what? I'm human. I'm human," Cueto said through an interpreter. "I just got to keep my head up and keep working. That's all I got to do."
The Reds' ace allowed more than two runs, more than five hits and failed to pitch at least seven innings -- all for the first time this season.
His final line: 5 1-3 innings, six hits, eight runs (six earned), six strikeouts. He hit the two batters in the seven-run sixth, when the Nationals blew the game open.
It was Cueto's shortest start since Sept. 16, 2013, and his most runs allowed since Sept. 22, 2010. His ERA rose from 1.25 to 1.86.
"He wasn't just the groundball machine, strikeout machine that he's been to this point," Reds manager Bryan Price said. "It's just the law of averages caught up with us today."
Denard Span went 5 for 5 with two runs, two doubles, two RBIs and a stolen base for the Nationals, and he used his speed to get the Reds to throw a couple of balls away. Cincinnati committed four errors -- twice as many as in any previous game this season.
The Reds have committed six errors thus far in a two-game series. They had only 13 all season before arriving in D.C.
"You're not going to go through the entire season with 12 errors," Price said. "This is a special defensive club. Outstanding. Just like inevitably Johnny was going to have a game where he wasn't going to have his best result, it was going to happen defensively at some point as well."
Doug Fister (1-1), making his home Nationals debut, allowed two runs and six hits over seven innings with good movement on his fastball.
But Span was the unstoppable agitator, and it paid off in the Reds' calamitous third and sixth innings.
Fister led off the third by reaching on an error when first baseman Todd Frazier couldn't backhand a grounder. Span then tried to bunt his way on and did even better, laying one down that prompted a wide throw from third baseman Ramon Santiago.
Fister scored all the way from first, and Span ended up on third and scored on Anthony Rendon's sacrifice fly to give the Nationals a 2-1 lead.
In the sixth, Span led off with a single, then stole second and went to third when catcher Brayan Pena's throw went into center field. Span scored on Jayson Werth's RBI single and eventually came around to bat again in the inning, bringing home two more runs with a double off lefty reliever Sean Marshall.
The evening's work raised Span's batting average from.239 to .263.
"I got more gratification just disrupting them and getting them to throw the ball away," Span said. "For me that's how I have to take over a game."
NOTES: Span's five hits tied a career high. ... Cincinnati 1B Joey Votto missed his fifth straight game with a strained left quadriceps. Price said he hopes Votto will return when the Reds open a homestand Friday. "We just remain optimistic that Joey's going to be ready to play when we get back." ... Reds RHP Mat Latos (left knee, right elbow) threw the equivalent of two innings in a simulated game and could be slotted for a minor league rehab start Sunday. ... Cincinnati OF Jay Bruce (left knee) is eligible to return from the disabled list Wednesday. ... Reds' RHP Alfredo Simon faces RHP Tanner Roark in Wednesday's series finale.