Park limited Boston to just three hits and had a season-high seven strikeouts over seven innings in the Rangers' 7-2 victory over the Red Sox on Friday night.
Except for a rough fourth inning, when he walked two before a triple, Park had little trouble against the World Series champions.
"Again, I kept pitches down, and in and out, and changes in speed," Park said. "Two runs, it doesn't bother me. I just kept pitching."
That wasn't always the case in his first three injury-plagued and disappointing seasons in Texas. Even with two years left on his $65 million contract, Park went to spring training this year not guaranteed a spot in the starting rotation.
Now Park (3-1) has consecutive wins over the New York Yankees
and Boston. The right-hander won just four games last season and was 14-18 in 48 Texas starts -- with five stints on the disabled list -- before this year.
"I feel much more comfortable," Park said. "Physically healthy, you can do a lot of things."
Park is even starting to earn the trust of manager Buck Showalter.
"He's had a great look in his eyes since spring started," Showalter said. "He's been sharp in most of his starts. He was the difference-maker tonight."
Tim Wakefield (2-1) retired 12 in a row until David Dellucci led off the decisive sixth with a single. Dellucci scored on Blalock's single to tie the game at 2, and Soriano followed with his fifth homer.
"I felt great, but I made one mistake to Soriano and it cost us the game," Wakefield said.
The Red Sox played without manager Terry Francona. Bench coach Brad Mills filled in as Francona served the first of his three-game suspension resulting from the bench-clearing scuffles in Tampa Bay last weekend.
Millar's drive deep into the gap hit off the heel of the glove of right fielder Gary Matthews Jr., who was in a full sprint when he lunged trying to make the catch. He ended up sprawled out on the warning track.
"You can't take a whole lot away from what Park did," Mills said. "He made the pitches and got key outs when he had to."
Filling the rotation spot of injured Curt Schilling, Wakefield gave up five runs and six hits with four strikeouts. His AL-leading ERA of 1.75 increased to 2.78.
The Red Sox played for the first time since Tuesday, having been rained out Wednesday in Baltimore before their scheduled off day Thursday. They have lost three straight and five of six.
Boston pitcher Bronson Arroyo, who starts Saturday, was suspended six games and right fielder Trot Nixon two games for their roles in the brawls in Tampa Bay. Both will appeal, and Nixon played Friday night, going 0-for-3. Ortiz plans to appeal his fine but wasn't suspended.
The Red Sox didn't allow a run in the first inning of their first 19 games, the only team to manage that. They have since allowed first-inning runs three straight games.
Texas led 1-0 in the first after Mark Teixeira hit a two-out single that dropped in front of Ramirez in left field. He scored when Blalock's high popup turned into a double when it fell between Ramirez and Johnny Damon.
"It was one of the balls he thought I would get and I thought he would get," Damon said. "It's something that shouldn't happen."
Boston (11-11) has 11 losses in April for the first since 1999. ... Right fielder Richard Hidalgo was out of Texas' starting lineup for the fourth time in seven games. He is mired in a 7-for-61 slump in his last 16 games and hitting just .181.