SAN DIEGO -- Chris Paddack arrived at Petco Park on Wednesday feeling slightly under the weather. You'd never have been able to tell.

Not by the way Paddack strolled into the Padres' clubhouse three hours before first pitch -- rocking a black paisley suit with a cowboy hat, his focus already laser sharp.

Not by the way Paddack shut down the Mariners over seven brilliant innings of one-hit ball -- dotting corners with fastballs and getting ugly chases with changeups.

“He reached down and the competition took over him,” said Padres manager Andy Green.

Paddack -- who struck out nine Mariners and retired the last 19 he faced in the Padres’ 1-0 win -- tossed and turned all night. He woke up sweating and achy. Team doctors examined him in the morning, noting no fever. But Paddack needed extra fluids during the game.

“I just tried not to let that affect me,” Paddack said.

Through five big league starts, Paddack certainly looks like the real deal. He got one run of support via Ian Kinsler’s 250th career homer in the second inning on Wednesday, and that was enough for the Padres’ 23-year-old rookie starter to outduel a six-time All-Star and 2010 American League Cy Young Award winner in Felix Hernandez.

“As a young kid, you know he has the name ‘The King’ for a reason,” Paddack said. “Going into this game, I told myself, this is a new generation. Let me show the world: ‘Why can't I beat him?’ That was pretty cool.”

Paddack allowed only three baserunners -- all in the first inning. He began the day with an uncharacteristic four-pitch walk.

Knowing Paddack felt ill, Green grew worried. The first three fastballs Paddack threw clocked in at 91 mph. The fourth was 90. They were four of the five slowest fastballs Paddack has thrown all year.

Asked for what his thoughts were at that time, Green was succinct.

“Uh-oh,” he said.

But Paddack bounced back quickly. After loading the bases, he ended the frame by getting Dee Gordon to flail at a changeup off the outside corner. Then he retired the next 18 Mariners, before he was removed after 83 pitches and a career-high seven innings.

“We got out of it,” Paddack said. “And then we were cruising.”

Paddack had his lead in the second inning, courtesy of Kinsler, who has faced Hernandez more than any other pitcher in his career. The Padres' second baseman appeared to be waiting on a first-pitch fastball, and he sent it off the facing of the Western Metal Supply Co. Building.

Kinsler opted not to reflect on his personal home-run milestone after the win, instead pointing to the Padres’ three-game winning streak and Paddack’s first victory. Count him among those impressed by the right-hander.

“How good he can be, it's up to him,” Kinsler said. “He obviously has the foundation and the makeup where the sky's the limit.”

Paddack lowered his ERA to 1.67. In five starts, he’s struck out 30 hitters and walked only eight. He would be an early favorite for the National League Rookie of the Year Award -- except his shortstop, Fernando Tatis Jr., extended his hitting streak to 12 games with a third-inning double.

Paddack will have his innings monitored closely this season after throwing only 90 last year in the Minors. He’s yet to eclipse the 90-pitch mark in any of his five Major League starts.

But when he’s on the mound, Paddack sure seems unflappable. He certainly was on Wednesday.