ST. PETERSBURG -- The Giants’ bats appeared to turn a corner after breaking out for seven runs in a series-salvaging win over the Nationals on Wednesday, but they reverted back to their sluggish state on Friday night at Tropicana Field.

Manager Bob Melvin was ejected for arguing balls and strikes in a 2-1 series-opening loss to the Rays, a sign of mounting frustration with San Francisco’s stagnant offense, which finished 0-for-10 with runners in scoring position during the first of six games in Florida.

The Giants had runners on first and second with two outs in the top of the seventh when home-plate umpire Clint Vondrak rung up designated hitter Jorge Soler on a called third strike to end the inning. The pitch -- a low-and-inside slider from left-hander Colin Poche -- appeared to be outside the zone, prompting Soler to voice his displeasure with the call.

Melvin emerged from the Giants’ dugout to argue as well, but he was quickly tossed by Vondrak, marking the 60th ejection of his managerial career and his first with San Francisco.

“He’s been calling the top of the zone the whole game and he called that one, which had not been called,” Melvin said. “It looked like it was way below the zone. In that situation, for me, it was pretty egregious.”

The Giants matched the Rays with six hits, but they couldn’t take advantage of multiple scoring opportunities, leaving nine runners stranded. They put the potential tying run at third with one out in the top of the ninth, but they couldn’t equalize after Nick Ahmed flied out to shallow left field and Jung Hoo Lee lined out to end the game.

San Francisco has hit only .152 with runners in scoring position in 11 games since March 31, the second-lowest mark in the Majors over that span. The Giants have been held to four runs or fewer in 11 of their first 14 games and haven’t gone deep in their last seven contests, their longest homerless streak since June 7-13 in 2014.

“We haven’t been able to do our jobs, especially me,” said Soler, who is batting .204 through his first 14 games. “When we’ve put runners in scoring position, I haven’t been able to drive them in so far.”

Lee single-handedly manufactured the Giants’ lone run against Rays right-hander Jacob Waguespack in the third. After lining a 2-1 fastball to the opposite field for a leadoff single, Lee recorded his first career stolen base and then advanced to third when catcher Ben Rortvedt’s throw eluded shortstop José Caballero and bounced into center field.

Lee went on to score on another defensive lapse from Rortvedt, who allowed a high cutter from Waguespack to sail to the backstop for a passed ball.

It wasn’t enough to support rookie right-hander Keaton Winn, who was charged with the loss after giving up two runs on five hits over five innings in his third start of the year.

Winn fell into a bases-loaded jam in the second after the first three batters reached on singles, but he came close to avoiding damage after countering with back-to-back strikeouts of Jose Siri and Rortvedt. Still, he couldn’t keep Tampa Bay off the board after issuing a two-out walk to Yandy Díaz that forced in the first run of the game.

“That was very, very frustrating,” Winn said. “Bottom line is I just have to be better. Command the baseball better. Free bases are not it.”

The Rays went ahead 2-1 in the third after Harold Ramírez delivered a two-out single and scored on Amed Rosario’s RBI double into the right-center field gap. The Giants appeared to have Rosario thrown out at third after cut-off man Thairo Estrada made a strong throw to Matt Chapman, but Rosario was awarded the base after Chapman was ruled to have obstructed his path to the bag.

“That’s going to look funny all year, I guess,” Melvin said of the interference error. “I’m not sure if [Chapman’s] supposed to jump out of the way. I don’t know. It looked like [Rosario] was out pretty easily, so it’s the first time we’ve seen it called like that.”