Ryan Zimmerman is greeted at the dugout after a solo home run in the first inning. (Patrick Smith/Getty Images)

Two years ago, Seattle Mariners General Manager Jack Zduriencik called his Nationals counterpart, Mike Rizzo, asking for a trade. The Mariners had their eye on outfielderRyan Langerhans, but the Nationals would only relent if they got their own prize: Michael Morse, a power-hitting prospect without a true position who had yet to harness his potential because of injuries.

In those two years since, and this season in particular, Morse has blossomed into an offensive force that the Nationals can count on. Saturday was no different, as one of baseball’s hottest hitters broke open a tie game in the sixth inning with a two-run homer to right field, powering the Nationals to a 4-2 win over the Orioles before 36,614 at Nationals Park. It was the eighth straight victory for baseball’s hottest team.

“We didn’t really know what to expect” of Morse coming into the season, Manager Jim Riggleman said following the win.

“The sky is the limit for him right now,” third baseman Ryan Zimmerman said. “His talent is just through the roof.”

With the score tied at 1 in the sixth, the 6-foot-5 Morse used his strength to drive an 87-mph change-up into the Nationals’ bullpen. Immediately, Orioles starter Brian Matusz flailed his arms in disgust. Morse rounded first with his right fist pumping in the air. It was Morse’s 13th home run of the season, and seventh when the score was tied.

After starting May with a .216 batting average, Morse has since hit .364 (47 for 129), with 12 home runs and 33 RBI. His slugging percentage is .728 since then. Morse has been the main offensive cog for the Nationals (35-36), who can reach .500 on Sunday by completing a three-game sweep of the Orioles (31-37).

“I’m just playing,” said Morse, who says he hasn’t changed his hitting approach since the beginning of the season. “Mentally, I’m challenging myself every day. I’m going up there and just trying to have good at-bats every day.”

Other than Morse’s bat, the Nationals have relied on their strong defense and pitching all season long. Despite not being as sharp as in his previous start, starter Jordan Zimmermann (5-6, 3.08 ERA) pitched an effective 61 / 3 innings for the win, allowing two runs on eight hits.

Zimmermann worked out of several jams, including a tough one in the fourth inning in which he gave up back-to-back hits. After Derrek Lee smacked a one-out double to left field and Felix Pie reached on a single, Zimmermann struck out third baseman Mark Reynolds on a full-count, 94-mph fastball. The right-hander then induced a weak groundball to Morse for the third out.

But after Zimmermann allowed a run on three singles in the seventh inning, Riggleman pulled him for reliever Henry Rodriguez, who got the inning’s last two outs and pitched a scoreless eighth. Drew Storen then pitched the ninth for his 17th save.

Earlier this season, the Nationals couldn’t string together multiple runs, let alone wins. Now they are enjoying their longest winning streak since an eight-game run in August 2009 and have featured a more consistent offense.

Since third baseman Zimmerman’s return from the disabled list, the Nationals are 5-0. Saturday was his strongest outing since coming back, with Zimmerman hitting a solo home run in the first inning (his first since coming off the DL) and reaching on a double to right field in the sixth inning — just before Morse’s two-run shot.

It has come full circle for Morse. After being drafted as a shortstop by the Chicago White Sox in the third round of the 2000 draft, the Florida native bounced from one minor league outpost to the next before being traded to the Seattle Mariners. There, he made his major league debut as a 23-year-old in 2005. But after that, knee, wrist and shoulder injuries plagued him. He was returning to form for Class AAA Tacoma when he was traded to the Nationals.

Morse has made strides since coming to Washington. In 98 games last season, he hit .289, smacked 15 home runs and drove in 41 runs while playing most of his time in the outfield. Saturday’s two-RBI game gave him 42 this season, a career high, with more than half of the year remaining.

Morse has credited the difference to a growth in confidence and the help of batting coach Rick Eckstein. His teammates see a player who has finally realized that he can be just as dominant as any of the best. It’s a promising future for Morse, and one the Nationals are excited about.

“He just learned,” Zimmerman said. “The more at-bats you get at this level the better you’re going to get. He’s obviously very talented, he was very highly sought-after when he first came up. And now, he’s got that light switch on.”