PITTSBURGH – For a late-in-camp spring tuneup, Lance Lynn's start on Monday was fine. Threw 95 pitches, got his work in, and put up zeros in three of his four innings.

Trouble was, Monday's game took place in frigid, 40-degree PNC Park, not balmy Florida, and Lynn's bad inning wasn't an exhibition footnote, but a game-deciding mistake. After Lynn, who had already given up a run, walked the bases loaded in the first inning, Pirates rookie Colin Moran slugged another misplaced fastball over the right-field seats for a grand slam, staking the Pirates to a five-run lead that barely survived for a 5-4 victory over the Twins.

"Realistically, one swing cost me four runs. And the walks didn't help the situation," Lynn said after a debut made even more deflating for having come after three shutout starts by his rotation peers. "If I'd made one good pitch there, we get out of that with just one run."

Things would have been quite different in that case, since the Twins held Pittsburgh to just five hits all day, and eventually struck for four runs of their own in the sixth inning, on a Brian Dozier home run and doubles by Miguel Sano, Eduardo Escobar and Max Kepler. But needing just one run to tie, they stranded runners in scoring position in the sixth, seventh and eighth innings.

"It's tough coming back from a five-run lead, but we had some good chances," said Dozier, whose third homer of the season is tied for the most in the majors in the early going. "I'm really proud of how the guys battled and battled."

Lynn equaled his career-high with six walks (and the Twins bullpen added five more), and it's not a stretch to imagine that his abbreviated spring training — Lynn signed with the Twins on March 13 and made only four appearances after that, two of them against minor-leaguers — didn't help.

Twins manager Paul Molitor said he doubted that mattered. Lynn's training camp "was a little bit rushed, we get that, but I don't really want to connect the two," Molitor said. "It was tough conditions. I'm sure for the pitchers, that ball is slick and dry and cold. We had trouble throwing it over, but that's going to happen."

The 30-year-old veteran refused to blame his lack of command on his short spring, but he also conceded that it will get better as he pitches more.

"It's my third game [against] experienced players, I've just got to get in the groove," said Lynn, who threw only 51 strikes among his 95 pitches over four innings. "Command will come once you get into the flow of the game, as the season goes on."

It was missing from the start on Monday, with Lynn walking leadoff hitter Josh Harrison on five pitches. Two pitches later, the Twins' streak of 21 straight consecutive shutout innings from their starters was over, when Polanco doubled off the center field wall, scoring Harrison.

Lynn's control of his fastball then got worse. He walked Starling Marte, and after striking out Josh Bell and getting Corey Dickerson to ground out, he got into an extended battle with Francisco Cervelli, finally walking him after Cervelli fouled off three straight 3-2 pitches.

That loaded the bases for Moran, and the rookie third baseman immediately ran the count to 3-0 against Lynn. The veteran starter threw a couple of strikes past him, but on 3-2 again — Lynn's 31st pitch of the inning — Moran unloaded. He turned on another 95-mph fastball and smashed it 405 feet, carrying over the right-field seats, just the second grand slam Lynn had ever allowed.

"I just ran it a little more middle than I want," Lynn said. "If I get it [inside] there, maybe he flies out or swings through it, but I ran it just enough back to the middle for him."

The teams have Tuesday off before finishing the two-game series Wednesday.