Matt Joyce tags up and scores in the sixth inning for the Rays' second run. (AP)

ST. PETERSBURG, Fla. — Clay Buchholz’ momentum kept going, but the same couldn’t be said for his team.

The Red Sox starter turned in his second straight solid outing, but it wasn’t enough to prevent a 2-1 Rays win over the Red Sox in the teams’ series opener at Tropicana Field. The problem for Buchholz and Co. came in the form or the Rays’ pitching staff, which limited the Sox to their lowest scoring output since April 29.

Buchholz lowered his ERA to 7.77 after allowing two runs on six hits, striking out six and walking one over five innings. It snapped a streak of five consecutive games in which Red Sox starters claimed quality starts.

Earning the win was Tampa Bay starting pitcher Jeremy Hellickson, who avenged his worst outing of the season (in which he allowed five runs to the Red Sox) by holding the Sox to one run on five hits, striking out six and lowering his ERA to 2.77. The Rays’ starters have the second-best ERA in the American League.

Here is what went wrong (and right) in the Sox’ 20th loss of the season:

WHAT WENT WRONG

- Buchholz notched another balk for the Red Sox pitching staff, which now has a major league high six after Franklin Morales added two more, himself. This one proved costly, with Buchholz allowing Carlos Pena to come in with the game’s first run after the pitcher double-clutched on a pickoff throw to first. It was Buchholz’ fourth balk of his career, and marked the second time a Sox pitcher has balked home a run.

- The sixth inning proved to be forgettable for Buchholz, who began the frame my taking a Matt Joyce liner off the left heel, resulting in a leadoff single. After being checked by the Sox’ medical staff, the starter proceeded to allow Pena to line a single into right field on the first pitch he saw, putting runners on first and third with nobody out. It ended Buchholz’ night at 87 pitches, paving the way to Andrew Miller.

- Miller, who had dominated left-handed hitters both in the minors and during his brief stint back with the Red Sox, induced a fly ball to right field off the bat of Luke Scott, the first batter the Sox’ reliever faced. But right fielder Cody Ross stumbled just before gathering in the fly out, failing to get good leverage on his throw home. The result was Joyce scoring with the go-ahead run.

- Bobby Valentine’s roll of the dice in the sixth — leaving in the lefty Miller to face right-handed hitting Elliot Johnson with Matt Albers warming up — with two outs and the bases loaded paid off. Miller, who had allowed a career .415 batting average against with the bases full, got Johnson looking on a 3-2 fastball to end the threat.

- Mauro Gomez came on to pinch-hit with Mike Aviles on first, representing the game-tying run, and one out in the seventh inning. But, in his second career major league at-bat, grounded into a 4-6-3 double play on the first pitch he saw from Jake McGee, ending the inning. Gomez struck out in his only other big league at-bat.

- While Will Middlebrooks didn’t add to his season total for errors (3), he did participate in a couple of iffy defensive plays. The first came when he scooped up an Elliot Johnson bunt when it looked like the spin was going to take the ball foul. Then the rookie failed to handle a back-hand play on a Will Rhymes hard grounder the third base line, allowing it to kick off his glove and toward the stands.

WHAT WENT RIGHT

- Daniel Nava continued to impress, this time driving in the Red Sox’ only run with a two-out, RBI single in the fourth inning, scoring Jarrod Saltalamacchia. Nava is now 9-for-19 with seven RBI this season.

- Scott Atchison came on with one out in the eighth with runners on first and third and got the job done. He initially fanned Jeff Keppinger, and then ended in the inning by getting Johnson to ground out to second to keep the Sox within a run.