"Here they come," Lester said. "Not like you didn't have a good game or anything."
The rookie third baseman homered down each of the lines Monday night, pacing a Boston attack that included homers by David Ortiz and Dustin Pedroia and resulted in an 11-5 victory over the Kansas City Royals that snapped a maddening five-game losing streak.
Middlebrooks, called up last week when Kevin Youkilis went on the disabled list, hit a three-run shot in the first inning and a two-run homer in the eighth, becoming the first player in Red Sox history with at least one extra-base hit in each of his first four major league games.
He also hit a grand slam in Boston's 17-inning loss to Baltimore the previous night.
"I just tried to carry over the way I started out this year," said Middlebrooks, who was hitting .333 at Triple-A Pawtucket when he got called up. "Just wanted to help the team win."
Felix Doubront (2-1) allowed all five Kansas City runs over 6 1/3 innings, giving the Red Sox bullpen a much-needed rest. Boston used up every available arm against the Orioles, forcing left-fielder Darnell McDonald to finish the 9-6 defeat.
Doubront left protecting a two-run cushion with the bases loaded in the seventh inning, but Vicente Padilla got Billy Butler to chop into an inning-ending double play to preserve the lead, and the Red Sox added four more runs in the eighth to put it away.
Padilla wrapped up the game for the 34-year-old's sixth career save.
"He did a great job to save me," Doubront said.
The Royals' Jonathan Sanchez (1-2) was pounded for six runs in three-plus innings, the 11th straight time the former Giants starter failed to last more than five innings.
Kansas City pitchers are averaging fewer than five per start, worst in the major leagues.
"I always feel the same out there," Sanchez said. "I go out there and give my 100 percent. Sometimes it goes your way and sometimes it doesn't."
Red Sox manager Bobby Valentine refused to make any roster moves to bolster the bullpen after their marathon at Fenway Park, reasoning that nobody deserved to get sent to the minors.
Doubront wasn't great, but he gave Valentine enough.
The left-hander got into trouble every inning but the fourth, yet he somehow managed to limit the damage each time. Doubront allowed seven hits and three walks on 111 pitches.
Of course, it's easier to pitch with a lead.
Adrian Gonzalez gave him that with an RBI single in the first, and Middlebrooks piled on moments later when he belted a three-run shot that just skirted the right-field foul pole.
Kansas City got half the runs back on an RBI groundout by Brayan Pena and a sacrifice fly by Chris Getz, but the Royals repeatedly failed to put together a big inning.
Ortiz homered to right field in the third. Kelly Shoppach led off the fourth with his first career triple, chasing Sanchez from the game, and Pedroia greeted reliever Nate Adcock by pounding a two-run homer into the seats in right-center field.
"What happened today, I didn't think I got hit pretty well," Sanchez said. "I made a good pitch to the guy who hit the three-run home run. When he hit it, he didn't know where it was. He got lucky. After that, the home run Ortiz hit, and that was it. I pretty much made good pitches."
The Royals still trailed 7-4 when Doubront came out for the seventh inning.
He allowed a leadoff single by Pena and one-out base hits by Alcides Escobar and Jarrod Dyson before getting Alex Gordon into an 0-2 hole. The Royals' left-fielder managed to work back for a full-count walk, bringing in a run and chasing Doubront from the game.
That's when Padilla took care of Butler with a chopping double-play ball to second base.
Boston piled on in the eighth inning.
Pedroia walked and Ortiz was put on base intentionally, and Cody Ross brought them home with a double to center. Middlebrooks then sent a pitch from reliever Tim Collins down the left-field line, the ball bouncing off the opposite foul pole from his first home run.
The Red Sox wound up with 16 hits, two shy of their season high, and the four homers were second only to the five they hit against Tampa Bay on April 14.
"I'm proud of these guys, taking that flight here after that game last night," Valentine said. "I know we're talking about small victories, but it's not easy to do what they did."
Notes: Boston RHP Daisuke Matsuzaka (Tommy John surgery) pitched 4 2/3 innings for Pawtucket on Monday in the third of his five scheduled rehab starts. ... Royals RHP Greg Holland (ribcage) left for what will likely be two rehab appearances at Double-A Northwest Arkansas. ... Boston LHP Jon Lester faces Royals LHP Bruce Chen on Tuesday night.