Karns is off and running (Karns through four)

After a rain delay of 1 hour, 21 minutes, Nathan Karns stepped on the mound at Nationals Park for the first time. It couldn't have been easy for the 25-year-old to have waited for his major league debut to begin while rain poured down here in D.C. He had to be jacked up as all get-out, but the wait is now over. If Karns was too juiced up in the first inning of his debut, it didn't show. Wearing No. 57 and facing Nate McLouth to open things up, Karns toed the rubber, turned into his smooth, causal windup and was off. The first pitch the right-hander threw in his major league debut was a 94 mph fastball just below the zone, called a ball by home plate umpire Tom Hallion. Three more heaters from Karns followed, the last of which retired McLouth on a groundout to second. Up stepped Manny Machado, who is hitting .460 in his last 10 road games. Karns didn't look intimidated by the major league leader in doubles, getting ahead of him 0-2 and then throwing a 97 mph fastball that PITCHf/x showed was in the zone by a good margin. It was called a ball. No matter. Karns got Machado on a grounder to second three pitches later. Karns then got Nick Markakis to ground out to first on the first pitch, with Adam LaRoche making a nifty grab on the high bouncer that went just over the bag and tossing it to Karns for the out. It goes down as an 11-pitch first inning in the bigs for Karns. He threw six pitches, worked at 94-97 with his fastball and threw just one slider to go along with 10 heaters. Pretty strong start from the rook. Karns was then handed a three-run cushion when LaRoche crushed a three-run homer to right-center off Orioles righty Kevin Gausman in the bottom of the first. It's LaRoche's ninth homer of the season, gives the Nationals a 3-0 lead, and might allow Karns to breathe a little easier as he comes out for his second inning of work in his big league career. Update: Karns got into a little trouble in the second, allowing a run and putting runners at the corners after three straight hits allowed to Chris Davis, Matt Wieters and J.J. Hardy. After a brief chat with LaRoche, who came to the mound to try and settle Karns down a bit, the right-hander bounced back, striking out Yamaico Navarro and Gausman, both swinging, to strand two runners and keep the Nats' lead at 3-1. It was a 25-pitch second inning for Karns, who needed to battle but showed nice composure in retiring the bottom of the O's order to avoid a crooked number. Update II: Two Karns fastballs left the yard in a hurry in the fourth inning, and this game is now tied 3-3. With one out in the fourth, Karns left a 95 mph heater knee-high and over the heart of the plate to Davis, and the Orioles' first baseman absolutely smoked it out to right for his 17th homer of the season. The ball flew out of here in the blink of an eye, coming down in the Nationals' bullpen. Two batters later, it was a 93 mph fastball from Karns that Hardy crushed into the visitors' bullpen in left to knot the game. This pitch was letter-high and Hardy went up and got it. Those are perfect examples of pitches that you can get away with at the Double-A level but cannot here in the bigs. You may be able to throw in the mid-to-high 90s and you may get ahead in the count, but major league hitters will crush mistakes. The ball to Hardy was a tough pitch to get to, but the one to Davis was right in his happy zone, and now we're all tied up. Manager Davey Johnson said before the game that he was probably going to limit Karns to about 80 percent of the number of pitches he'd usually throw, so with Karns now at 72 pitches through four, he might only get one more inning here tonight.