CHICAGO -- After emerging as the Chicago White Sox's ace last year, Chris Sale picked up right where he left off in his first career Opening Day start Monday afternoon.

Sale threw 7 2/3 scoreless innings, and Tyler Flowers' home run stood up as the winning margin in Chicago's 1-0 victory over the Kansas City Royals on a frigid afternoon at sold-out U.S. Cellular Field.

It was also the first start for Sale since he signed a five-year, $32.5 million contract extension on March 7. If the freshly minted deal made him nervous, it didn't show.

Sale was efficient and effective despite needing to escape from a couple of tight spots.

"It's in the past, it's over with," Sale said of his contract. "I just have to go out and be the same guy I was last year and the year before and the five to 10 years before that. It's a game. You can't get caught up in this or that or the business of it. You just go out and have some fun and not even pay attention to it."

Sale threw 104 pitches (72 strikes) and struck out seven, allowing seven hits and one walk. He got out of some sticky situations by inducing big double plays in the fifth and seventh innings and wiggling out of a bases-loaded jam in the third.

The Sox bullpen then slipped out of a tight spot in the eighth thanks to Matt Thornton striking out Mike Moustakas to strand runners at first and third. Chicago closer Addison Reed pitched a scoreless ninth for the save.

In addition to strong pitching, the Sox also got a dazzling play by second baseman Gordon Beckham in the seventh, when he dived to snare a line drive by Lorenzo Cain.

"We have to play defense," Chicago manager Robin Ventura said. "This is a good team we're playing. You just can't give more chances to the other side. For us, pitching and defense is going to be key, and then find a way to score some runs."

The loss continued a losing trend on Opening Day for the Royals, who breezed through spring training. They're now 15-30 in openers, and they dropped to 5-17 starting the season on the road. The good news for Kansas City is that James Shields, whom they acquired in December in a blockbuster deal with Tampa Bay, had a strong outing.

Shields (0-1) went six innings, struck out six, scattered eight hits and didn't walk anyone while looking like a solid No. 1 starter.

His lone mistake was throwing a second changeup in a row to Flowers leading off the fifth. The White Sox catcher swatted it through the frigid air over the left-center-field fence to give Chicago a 1-0 lead.

"Sale was phenomenal and James Shields was phenomenal," Royals manager Ned Yost said. "The difference in the game was one high changeup (to Flowers), and that was it. It was a cold day, but the pitching was pretty darn spectacular on both sides, I thought."

Both starters struck out five through the first four innings, and a few came in big situations to keep it scoreless.

The Sox were the first to threaten, as they got back-to-back singles with one out in the second by Dayan Viciedo and Alexei Ramirez. Shields, however, got Tyler Flowers looking and Beckham swinging to strike out the side and close the frame.

Sale returned the favor in the top of the third by getting out of a bases-loaded, one-out jam by striking out Billy Butler and getting Moustakas to pop out. The Sox lefty ace also got out of the fifth after allowing a leadoff single when Chris Getz grounded into a double play and Alex Gordon grounded out.

"He did a good job of keeping his emotions in check," Ventura said of Sale. "He was excited, but I think this is what you expect in a lot of ways of him going out and being effective and getting outs and things like that. He's a special kid, so I think in some ways we expect a lot out of him, and this is some of that stuff."

The flip side was what happened to the Royals bats in those situations. After being one of the best offensive teams in the majors during spring training, the Royals just couldn't come up with the big hit when they needed it most.

It probably didn't help that it was 44 degrees to start the game and 36 at the conclusion, but weather isn't what kept clutch hits from coming at important times.

"Anytime you've got two horses on the mound like that, you're just looking for a big hit," said Kansas City first baseman Eric Hosmer, who went 1-for-3 with a walk and stole second in the ninth to put himself in scoring position. "We had some opportunities and hit some balls hard, and that's just the way it goes. When you're facing a guy like Sale, you can't let those opportunities go."

Reed induced a groundout from Jeff Francoeur for the final out.

NOTES: After going 54-37 against Kansas City from 2006-2010, the White Sox were just 13-23 combined against the Royals in 2011 and 2012. ... Former White Sox star Bo Jackson threw out the ceremonial first pitch to former teammate Ventura. ... Paul Konerko made his 13th straight Opening Day start for the Sox, extending his franchise record. Colorado's Todd Helton is the only other active player with more consecutive season-opening starts with the same franchise, 16. ... Shields went 4-0 in five April starts a year ago. With Monday's loss, his career April record fell to 15-4 in 32 starts. ... Twenty of the players on the Royals' 25-man roster are younger than 30.