PAWTUCKET — The count was 1-and-2 to the first batter for the Pawtucket Red Sox in the bottom half of the fourth inning of a scoreless game when the sellout crowd began to chant.

“Pa-pi! Pa-pi! Pa-pi!”

“When they start calling your name,” said Big Papi, aka David Ortiz, “it puts you in the mood.”

Big Papi proceeded to put the next pitch from Toledo right-hander Virgil Vasquez out of the park, a swing that greatly improved the mood of Red Sox fans from coast to coast as the defending World Series champions start the second half of the season tonight in Anaheim.

The ball got out in a hurry — a line drive that rocketed over the low fence in front of the visiting bullpen in right field, a cozy 330 feet from home plate.

While it wouldn’t have been a homer at Fenway Park, which isn’t as friendly to left-handed batters as McCoy Stadium, it nevertheless was a powerful indication that Big Papi will soon be back in Boston, swinging for the fences.

Before the game — the first of what is expected to be seven minor-league outings (four in Pawtucket, followed by three for Double-A Portland) for Ortiz as he rounds out his rehab from a partially torn tendon sheath in his left wrist that has kept him on the sidelines since May 31 — the big fellow was asked whether he’d be swinging for the fences.

“Don’t I always?” he replied with a smile.

He was swinging hard in batting practice, nearly decapitating PawSox manager Ron Johnson, who was pitching, with a liner back to the mound.

“I tried to swing the way I normally do — the hardest I can,” Ortiz said.

The last month-and-a-half has been hard on Big Papi, who loves to play the game and, as one of the team leaders in the clubhouse, suffered when the Sox fell behind the surprising Rays in the A.L. East.

But with the Red Sox having regained first place just before the All-Star break, and with Big Papi’s big bat about to return to the lineup, prospects for another postseason run are brighter than ever.

If Big Papi was feeling any pressure last night, he certainly didn’t show it. He slept on the ride down Route 95 to Pawtucket, as a friend drove his white Cadillac Escalade to the ballpark.

Fans awaiting his arrival greeted the Papi Mobile with a reverence suitable for the Pope Mobile, while Johnson tried to keep expectations at a reasonable level.

“He’s no different than anybody else,” the PawSox manager said. “He’s got to see pitches.”

The thing is, Ortiz is different. He hits a baseball like nobody else.

He has batted .300 in three of the last four seasons while hitting 41 homers in 2004, 47 in ’05, and a career-high 54 in ’06. He has driven in at least 101 runs in each of the five seasons since he came to Boston from Minnesota, averaging more than 128 a year.

His postseason numbers have been similarly impressive. He has hit .313 in 18 ALDS games, .320 in 26 ALCS games, and .321 in eight World Series games — playing a key role in Boston’s four-game sweeps of St. Louis in 2004 and Colorado last year.

So there was understandable concern when Big Papi had to shut it down after a particularly painful swing in Baltimore on May 31.

Last night’s game — played in front of the fifth-largest crowd (11,460) in PawSox history — was the first time Ortiz has swung a bat in competition since he faced the Orioles.

Asked after batting practice whether he was concerned about being rusty, Ortiz replied with his customary good humor.

“I’m too old to be rusty,” he said.

It certainly didn’t take Ortiz long to work out any kinks that may have crept into his swing.

After popping out to shortstop on a 2-2 pitch as the third batter in the first inning, Big Papi had his Big Blow in the fourth.

He fell behind quickly in the count, 0-2, taking a called strike and then chasing a high fast ball. He then took a ball, after which the crowd, which had given him a standing ovation before his first plate appearance, began to chant his name.

They quickly went from chanting to cheering as Ortiz rocketed a line drive over the fence in right.

“That’s my game,” he said to a media throng outside the door to the PawSox clubhouse. “After the way I was hurting, it was a good feeling to be able to swing like that.”

Ortiz’s blast was one of three in the fourth inning — George Kottaras and Jeff Bailey each had two-run shots — as Pawtucket exploded for seven runs on their way to a 15-6 mauling of the Mud Hens.

The PawSox batted around in that big inning, bringing Big Papi to the plate again with two outs and nobody on. He again hit the ball hard, but this time it was a liner right at the first baseman.

“I put a good swing on that one, too,” Ortiz said.

Big Papi’s last at-bat came in the sixth, when he again was the leadoff batter. He took a healthy — emphasis on “healthy” — swing at the first pitch, and missed. He took the next three pitches for balls, then fouled off two pitches before laying off a low breaking ball and drawing a walk, after which he was lifted for a pinch-runner.

“I chased a few high fastballs,” he said, “but other than that, I was taking the ‘bad’ pitches.”

It was a good night for the big guy.

“The fans were unbelievable,” he said. “They made me feel like I’m family.”

BIG PAPI’S PERFORMANCE

jdonalds@projo.com