(SportsNetwork.com) - Mentor faces student and streaking pitcher faces streaking pitcher on Monday night when the Baltimore Orioles visit the Washington Nationals at Nationals Park to begin the first half of a four-game home- and-home interleague series.

The teams will open the four games with two in Washington before heading to Camden Yards for games three and four in Baltimore.

Monday's game is the first between managers Buck Showalter and Matt Williams, who had a manager-player relationship when Showalter led the Arizona Diamondbacks and Williams was still an active player between 1998 and 2000.

Both now have teams in the thick of their divisional races, with Showalter's Orioles leading the American League's East and Williams' Nationals a half-game behind Atlanta in the NL East.

"We have to I think worry about our own games," Williams said. "We can't worry about what they're doing or how they're playing or any of that."

Williams sends out red-hot starter Stephen Strasburg, who's unbeaten in his last nine starts at home, including a 7 2/3-inning stint on Tuesday that yielded a 7-1 defeat of Colorado.

He's 6-0 at home in that stretch with a 2.08 earned run average.

"I just tried to execute pitches better," he said. "I wasn't trying to reinvent the wheel."

His only career meeting with the Orioles ended in a 9-3 win after he allowed an earned run in five innings on May 30, 2012.

The Orioles reply with lefty Chris Tillman, who's not lost in 10 road starts this season -- going 6-0 with a 5.53 ERA -- while winning just once in eight home starts.

His ERA at home, however, is much lower at 2.74.

In two career interleague meetings with Washington, he's gotten a pair of no- decisions and compiled a 6.52 ERA.

On Sunday in Boston, J.J. Hardy singled home David Lough in the top of the 12th inning to lift the Orioles to a 7-6 win over the Red Sox in the finale of a three-game set at Fenway Park.

Lough tripled to center field off Edward Mujica (2-4) to open the 12th and Hardy followed with a grounder to left. With one away in the bottom of the 12th, David Ortiz tried to stretch a one- hopper off the Green Monster into a double, but was thrown out at second. Zach Britton earned his 14th save by striking out Mike Napoli to end the game.

Brad Brach (4-0) picked up the win after tossing three scoreless innings.

In Washington, Ryan Zimmerman's RBI single in the eighth inning gave the Nationals a 2-1 win over the Chicago Cubs.

Denard Span legged out a double after poking one down the right field line to lead off the home eighth against Pedro Strop (1-4). Strop retired the next two batters and intentionally walked Adam LaRoche to set up a force at any base, but Zimmerman made him pay by lacing a single to left. LaRoche was tagged out trying for third to end the inning, but Span had already crossed the plate.

Tyler Clippard (6-2) escaped the eighth inning unscathed and Rafael Soriano tossed a 1-2-3 ninth to secure his 21st save of the season.

Baltimore won its series with the Nats, 3-1, a year ago.