The Sox’ Jason Bay, right, just misses a home run in the seventh inning last night as Royals center fielder Mitch Maier, above, can’t glove the ball, but it rolled along the top of the wall before being knocked back into play.

MCT / John Sleezer (above), and AP / Ed Zurga

KANSAS CITY, Mo. — A common phrase around the Red Sox clubhouse involves players or manager Terry Francona noting that something or another has to happen “if we’re going to be who we want to be.”

What they want to be, of course, is champions again and it will be hard for them to earn that designation without Josh Beckett being the pitcher he was a year ago.

For much of this season, Beckett has been decidedly average. Two fellow starters got to double figures in wins before he did and his ERA heading into last night was a mediocre 4.15.

But last night, Beckett looked like he did a year ago when he won 20 games and then was the dominant pitcher in the postseason. Snapping a personal three-game losing streak and earning a victory for the first time in almost a month, Beckett pitched 6 2/3 innings, allowing two runs on four hits as the Sox romped over the Kansas City Royals, 8-2.

It didn’t hurt that the team backed him with a 13-hit attack, the kind of offensive support that hasn’t happened in many of Beckett’s starts this season. In his eight losses, for example, the Sox have scored just 10 runs while he’s been in the game.

“This,” said Jason Varitek, “was the first time we’ve scored runs for him in a while.”

Beckett was touched for a run in the first, then threw five shutout innings after that, allowing just two hits in that span.

Meanwhile, the Sox scored in the fourth, fifth, sixth and seventh innings, extending their lead and providing Beckett with some room to operate.

Last night, he didn’t need much.

“He established his fastball and breaking ball early,” said Francona, “and that gave him two really good pitches.”

“Any time you’ve got two pitches you can throw for strikes,” said Beckett, now 10-8, “it makes it pretty tough on them.”

In the seventh, after a one-out double by Alex Gordon and a two-out walk to Ross Gload, Francona thought he noticed Beckett coming out of his delivery though the starter was at just 90 pitches.

Mike Timlin took over and after yielding a bloop single to Mitch Maier, retired the next four hitters. Chris Smith pitched a perfect ninth and the Sox remained three games behind the Tampa Bay Rays in the A.L.East.

Leading the lineup was newcomer Jason Bay, who had four hits for the eighth time in his career. Bay has hit safely in all five games with the Sox and has knocked in six runs, including two last night.

He doubled in the fourth to score Mike Lowell (walk) to put the Sox ahead for good, singled to kick off a two-run sixth, then belted a run-scoring double in the seventh.

“That felt pretty good,” acknowledged Bay, “to personally have some excess and also win the game. Hopefully, I can keep riding the wave and we can keep winning.”

Bay nearly had his second homer as a member of the Red Sox in the seventh when center fielder Mitch Maier almost gloved his belt to left-center, only to have the ball land on top of the wall and roll about 10 feet before left fielder Ross Gload swept it back into play.

Asked if he felt cheated, Bay shrugged and smiled. “Depends on how you look at it, because the center fielder almost caught it. It was one of the more interesting plays I’ve ever seen. You take what you can get.”

Rookie shortstop Jed Lowrie matched Bay’s two RBI with a two-run triple — his second triple in the last three days — scoring Lowell and Bay in the seventh.

Jacoby Ellsbury contributed two singles from the bottom of the batting order and also stole two bases, his first since July 1.

Ellsbury had gone 21 games without stealing and had been gunned down in each of his last three attempts. But after singling off starter Brian Bannister to open the fifth, he took off and swiped second, later scoring. In the sixth, he chipped in a run-scoring single to right and stole again.

“Even when he wasn’t been stealing,” said Francona, “he’s been an intelligent baserunner. They’ve been using the slide step on him, but tonight, he got in a situation where he could steal and he did.”

smcadam@projo.com