(Sports Network) - The Boston Red Sox try to turn around a sudden slump when the American League East leaders play the middle test of a three-game series with the Baltimore Orioles tonight at Fenway Park.

Boston saw its sizeable lead over the rival New York Yankees atop the division shrink to five games after dropping three straight times to the Bronx Bombers prior to this set. The losing streak was extended on Friday, when the Orioles finally put an end to their nine-game slide by holding on for a wild 9-8 victory.

Nick Markakis went 3-for-5 with a three-run homer and Miguel Tejada finished with two RBI for Baltimore, which hasn't won back-to-back games since taking two in a row from the Yankees from August 14-15.

Kurt Birkins (1-1) got the win after allowing just one run over three innings in relief of starter Radhames Liz, who gave up a pair of runs in three-plus frames of work.

Julian Tavarez (7-10), a fill-in for pregame scratch Tim Wakefield, took the loss for Boston. The right-hander surrendered four earned runs on seven hits in 3 1/3 innings.

Wakefield, who was going attempt to become the majors' first 17-game winner this season, did not pitch because of a sore lower back and is questionable to make his next scheduled turn in the rotation.

Dustin Pedroia banged out four hits and scored twice, while Mike Lowell went 3-for-5 to lead the Boston offense. Eric Hinske also had three hits, while David Ortiz belted a solo homer.

The Red Sox managed to maintain their five-game cushion over the Yankees following New York's 9-1 loss to Tampa Bay on Friday.

Tavarez was initially slated to start tonight's contest. The assignment will now go to rookie Clay Buchholz, who will try to build off last month's successful big league debut.

Buchholz, considered the top pitching prospect in the Boston system, was promoted from Triple-A Pawtucket to start one game of a doubleheader with the Angels on August 17. The 23-year-old earned his first major league victory by holding Anaheim to four runs -- three earned -- and striking out five over six innings in the Red Sox' 8-4 decision.

The 2005 supplemental first round selection went 8-5 with a 2.44 earned run average in 24 games (23 starts) between Double-A Portland and Pawtucket this season.

Baltimore was expected to send out ace Erik Bedard this evening, but the standout lefty was scratched due to a strained oblique muscle. In his place will be rookie Garrett Olson, who is 1-2 with a 7.33 ERA in five starts with the Orioles this season.

Olson last pitched in the majors on August 22, when he was tagged for six runs over five innings in a no decision against Texas. The 23-year-old was sent to Baltimore's Rookie League affiliate in Bluefield last week, but was quickly recalled when rosters expanded today.

The young left-hander faced the Red Sox at Camden Yards on August 11 and came away with a loss after yielding four runs on eight hits over 6 1/3 innings.

Boston has won seven of 12 meetings with Baltimore this season and is 22-8 in the overall series since the start of the 2006 campaign. The Orioles have lost 12 of 16 games at Fenway Park over that span.