Karns allowed four runs on five hits over his three frames. He walked three, hit a batter, allowed a home run and struck out two.
He needed 74 pitches to get through three innings and retired just nine of the 18 hitters that he faced.
Over his three starts with the Nats, Karns went 12 innings, allowed 17 hits and 10 earned runs. He surrendered five home runs, walked six and struck out 11.
The 25-year-old showed potential, but he isn't ready for this level just yet. Karns was promoted to the bigs after making just nine starts above high Single-A ball because of injuries within the Nats' system, and he needs some more seasoning before making his way back up here for a longer stretch.
The Nats, meanwhile, trail 4-2 in the fourth. Jayson Werth is 2-for-2 with two RBI singles, but Pedro Florimon's two-run homer in the third has given the Twins a little cushion.
Craig Stammen has come on to replace Karns, and the Nats would love it if Stammen could match what he did in Atlanta last weekend and go for a while.
Update: With nobody out in the bottom of the fifth, the sky suddenly opened. Out of nowhere, it started pouring, and we're now in a rain delay.
The rain was so unexpected and forceful that I heard shrieks from people in the upper deck. It looks like this might just be a passing shower, though.
I'll keep you posted.
Update II: After just a 12-minute delay, Game 2 of the doubleheader has resumed here in D.C.
Rendon made a leaping grab of a Jamey Carroll liner in the top of the sixth, a play that saved a run and will surely make a few highlight reels. The 22-year-old got up to make that play.
Rendon then singled leading off the bottom half of the sixth, and he came around to score on Span's two-out, RBI triple into the right field corner. It was Span's sixth triple of the season, which ties him for the second-most in the majors.
We've got a tie ballgame here in D.C., and what's been a very long day could give us a pretty exciting finish to the rubber game of this series.
Update IV: The Nats have taken their first lead of the nightcap of this doubleheader, with Adam LaRoche and Ian Desmond hitting doubles on consecutive pitches to plate the fifth Nationals run of the night.
Desmond's double extended his hitting streak to 12 games. During that stretch, he's batting .340.
It's 5-4 Nationals after seven, and Drew Storen is coming on to work the eighth.
Update V: The Nats put up 12 runs in today's doubleheader, five of which came in tonight's 5-4 win that gave the Nats a sweep of the doubleheader and a series win, as well.
Final quotes to come.