Two ninth-inning hits by catcher Dioner Navarro loom large for the American League East-leading Tampa Bay Rays. Both game-winning knocks against Boston, one each at Fenway Park and Tropicana Field, sparked the Rays to key victories after they had lost series openers to the second-place Red Sox.

It’s hard to overestimate the value of those victories, as the Rays avoided a possible collapse after having Boston close in on their division lead. Although the Rays have led the AL East since winning their first game of the second half, they have had to hold off the defending champion Red Sox down the stretch.

Tampa Bay held a 5.5-game bulge over Boston at the start of September, but the lead had slipped to 1.5 games when the Rays traveled to Fenway for a three-game set on Sept. 8. After Jon Lester and Jonathan Papelbon blanked Tampa Bay in the Monday night matchup -- the Rays’ ninth straight loss in Boston -- the lead dropped to a half-game.

In the second contest, the Rays trailed 4-3 heading into the ninth with first place on the line. September callup Dan Johnson tied the game with a leadoff blast off Papelbon, and three batters later, Navarro doubled home Fernando Perez with the go-ahead run in a 5-4 victory. In the rubber game on Sept. 10, a three-run homer from Carlos Pena in the 14th inning secured Tampa Bay’s first series victory in Boston since 1999.

Following the Fenway hookup, Boston took three of four games from Toronto while Tampa Bay lost two of three at Yankee Stadium, reducing the deficit to a single game when the Red Sox came calling at the Trop Monday night.

The Red Sox scorched Tampa Bay ace Scott Kazmir for four homers and nine earned runs in the series opener, as the Rays lost their third straight game and had their lead dwindle to mere percentage points.

Tuesday’s pitchers’ duel between Josh Beckett and Andy Sonnanstine was scoreless until Boston broke through with a run in the sixth. It seemed appropriate that Beckett would lead the Red Sox to the top of the AL East, but Pena tied the game with a seventh-inning home run -- and the deadlock carried into the ninth. The Rays managed to hold on to first place when Navarro singled to center with the bases loaded and one out, driving in the winning run in the ninth for the second time in a week against the defending World Series champions.

After avoiding a fourth consecutive loss, the Rays rolled to a 10-3 win Wednesday, giving them a two-game lead. Facing a playoff atmosphere and rebounding from first-game losses in both series have to be a confidence-builder for the young Rays.

That’s not to say the AL East race is over, of course. The Red Sox offense has been firing on all cylinders, averaging a major league-high 6.14 runs per game since the start of August.

Who needs Manny Ramirez? Run production has come from up and down the Boston lineup. Since Aug. 1, five Red Sox players have recorded 30 or more RBIs going into Thursday’s action: David Ortiz (37), Kevin Youkilis (36), Jason Bay (34), Jed Lowrie (33) and Dustin Pedroia (31), who also leads the majors with 41 runs scored since Aug. 1. Only the Mets, Yankees and Orioles have as many as three players with 30+ RBIs in this span.

At the same time, the Rays have been playing without Carl Crawford and Evan Longoria. After sitting out five weeks with a fractured wrist, their rookie third baseman returned earlier than anticipated last weekend, but didn’t show much pop until erupting for three home runs Thursday night against Minnesota.

With the recent struggles of Minnesota and the Chicago White Sox, the two AL Central contenders, both Boston and Tampa Bay are going to play October baseball. Still, what a boost it would be to the Rays to claim their first-ever division title, rather than settling for the wild-card berth after leading the AL East for nearly the entire second half.