CHICAGO -- The Kansas City Royals needed Danny Duffy to have his best start of the season Sunday at U.S. Cellular Field, and that is just what he gave them in the Royals' 4-1 victory against the Chicago White Sox.

Duffy out-pitched Chris Sale, Chicago's ace left-hander, and gave the Royals' taxed bullpen a day to catch its collective breath. He pitched into the ninth by tying his season high in pitches (113) and struck out four to earn the win in his first outing since July 10.

"I've thought about how bad we've needed an efficient start before, and I tried to pitch to that so much that I overdid it," Duffy said. "Today I just tried to execute. I'm finally starting to learn that when you have the best defense in the league behind you, all you've got to do is execute."

The only run Duffy allowed on six White Sox hits was a lead-off homer in the ninth by Chicago third baseman Tyler Saladino. Duffy's performance was a welcome sight in the visitor's dugout. The only reliever who didn't pitch Saturday in a 13-inning game was right-hander Joe Blanton, and he was one of just two relievers available to manager Ned Yost on Sunday.

Blanton closed out the game for his first career save, but the main stories of this game were Duffy and the excellent defense the Royals played behind him.

"We needed him to stand up today, big time, and he did," Yost said. "We didn't have a bullpen. We needed Danny to go deep in the game. He managed his pitch counts. I was sitting there at the end of the game trying to decide which was more impressive, Danny's outing or our defense today. It's a tough call."

Kansas City's offense also came through with some key hits off Sale, who was rusty in his first start since July 11.

Center fielder Lorenzo Cain remained hot at the plate by going 1-for-4 with a solo homer off Sale in the sixth. First baseman Eric Hosmer went 3-for-4 with an RBI single in the first, and left fielder Paulo Orlando went 1-for-4 with a two-run homer off Sale to make it 4-0 in the seventh.

Kansas City (55-35) solidified its position atop the American League Central by winning three of the four games against Chicago (42-48), which dropped back into last in the Central -- 13 games behind the Royals.

Kansas City heads home to face the Pittsburgh Pirates on Monday. The White Sox, who have lost four of their past five games, host the St. Louis Cardinals for a two-game series starting Tuesday.

"We battled the first few games," Chicago manager Robin Ventura said. "This one, Duffy was tough. You have to tip your hat to them because they played better than us in this series, but I think even (Saturday) we had a chance to win it and it didn't happen. But I like the way our guys battled. Today, they just played better than us."

Sale went 6 1/3 innings and struck out six, but allowed four runs on 11 hits.

That included the homers by Cain and Orlando, which were just two of the numerous good swings Kansas City hitters got against Sale. He didn't look sharp for most of the outing, and gave up the game's first run in the top of the first despite striking out two.

Sale gave up singles to three of the first four hitters he faced, and Hosmer's drove in a run to give Duffy a 1-0 lead to start the game.

"This is not a good team to leave fastballs over the plate to, and also not a good team to let the ball travel over the fence," Sale said. "They take advantage of every opportunity you give them and that's what happens."

Chicago nearly rallied in the second, getting two runners aboard with one out, but shortstop Alexei Ramirez hit a grounder that Duffy fielded to start an inning-ending double play. The White Sox also put runners at second and third in the sixth, trailing 2-0, but Duffy struck out designated hitter Jose Abreu and left fielder Melky Cabrera to end the threat.

NOTES: The White Sox designated 3B Conor Gillaspie for assignment Sunday to make room for RHP Matt Albers to come off the 15-day disabled list and rejoin the bullpen. Gillaspie, 28, hit .237 with three home runs and 15 RBIs in 58 games in his third season for the White Sox. The move makes room for 3B Tyler Saladino, recalled last week, to stay on the roster and start regularly. ... The Royals optioned LHP Brandon Finnegan to Triple-A Omaha and recalled RHP Yohan Pino from Omaha. Manager Ned Yost said Finnegan would have been optioned Monday, when RHP Kris Medlen comes off the 60-day disabled list to join the bullpen, but Finnegan pitched in Saturday's 13-inning win that taxed the bullpen. Pino is a long reliever who was one of only two pitchers Yost had available out of his bullpen Sunday.