The Arizona Diamondbacks continued to seemingly regain their footing in the young season as they beat the Washington Nationals in D.C. on Tuesday. Unfortunately for the Nats, it was their fifth-straight loss and the home debut of baseball's top prospect, 19-year-old left fielder Bryce Harper.

For the D-Backs, it was their third-straight win and fourth out of five on the current East Coast road trip.

D-Backs starting pitcher Trevor Cahill had the slumping Nats off-balance all night, throwing 7.1 innings and giving up just one run on six hits and a walk. He also struck five batters en route to improving his record to 2-2 and lowering his earned-run average to 3.10.

Justin Upton seems to be coming around, going to 2-for-4, with a stolen base and two runs batted in. Upton, the offensive centerpiece of the Diamondbacks is now batting .257. Miguel Montero, John McDonald, and Aaron Hill also drove in runs for the D-Backs, who now stand at 13-11 on the season.

For Harper, the number-one pick in the 2010 draft, it was an inauspicious debut at the plate, as he went 0-for-3 at the plate with a strikeout. Called up to the big leagues, when star third baseman Ryan Zimmerman went on the DL, Harper is now 2-for-9 in his major-league career with one RBI. Harper did show off his arm for the National faithful when he nearly gunned down McDonald at the plate in the seventh inning after Upton hit a sacrifice fly to left. Harper ripped a 300-foot throw on the fly that nearly nailed McDonald.

The two teams square off again today at 4:05 p.m. with Joe Saunders (2-1) taking the hill against Edwin Jackson (1-1). TV: Fox Sports Arizona. Radio: KTAR 620 AM. More info: www.dbacks.com.