TORONTO -- Bruce Chen must enjoy the heat because he has a knack for winning in August.
"I was throwing strikes. I was using all my pitches," Chen said. "I had really good command of my curveball, my cutter and my changeup. Today is one of those days where everything was working in and out and I was changing speeds very well."
Chen (9-5) struck out nine and improved to 4-1 with a 3.68 ERA in five August starts this year. He is 18-9 in 61 career August games, his most wins in any month.
"Everything was firing on all cylinders for him," Royals infielder Mike Moustakas said. "When Skip came out there and took him out he said it's the best he's seen Bruce pitch in a while. He was dominant for us tonight."
Royals manager Ned Yost called Chen's performance "spectacular." The left-hander allowed three runs and four hits in 7 2/3 innings. He walked one and matched his career high for strikeouts.
It had been more than a decade since Chen's last nine-strikeout game on June 13, 2001, at Tampa Bay. Of his 92 pitches, 67 were strikes.
"He kept us on our feet and kept them on their heels," Moustakas said.
Jeff Francoeur matched his career high with four hits as the Royals, who had lost six of seven away from home, banged out 16 hits to open a 10-game, 10-day road trip on a winning note.
"Our attack was well-balanced," Yost said. "We drove the gaps, we did a nice job in our situational hitting and got big hits when we needed to."
Chen was perfect through three innings before Yunel Escobar singled to open the fourth, snapping an 0-for-17 slump.
"Chen did a very good job of keeping us out on our front foot, disrupting our timing," Blue Jays manager John Farrell said.
Kansas City came in having lost seven of nine overall and 21 of its previous 28 in Toronto but jumped on Blue Jays right-hander Brandon Morrow with a three-run, four-hit second.
Hosmer led off with a homer to center, his 11th and first since July 27 at Boston. Francoeur doubled and Johnny Giavotella followed with an RBI single to center, advancing to second on Colby Rasmus' fielding error. Salvador Perez capped the rally with an RBI single.
The Royals chased Morrow in the fifth, scoring three more runs. Butler hit a one-out homer to left, his 16th. Hosmer singled, stole second and scored on Giavotella's double. Perez ended Morrow's night with an RBI triple to right.
Morrow (9-8), who declined to speak with reporters, lost for the third time in four starts, allowing six runs and a season-high 11 hits in 4 2/3 innings. He walked one and struck out five.
"He's been really good against us and today it looked like he didn't have good command of his off-speed stuff," Butler said. "His fastball was a little up and just hitting too much of the plate."
Escobar had the only big hit of the night against Chen, a three-run homer to center in the sixth, his 11th.
"That's about the only (mistake) he made," Yost said.
Chen responded by setting down the next seven batters in order.
Blue Jays right-hander Joel Carreno made his major league debut in the sixth and worked 3 1/3 scoreless innings.
"He was calm, he was poised -- at least outwardly," Farrell said. "Inside he might have been going pretty quick with emotion. He made pitches with men in scoring position and got a couple of strikeouts. He did a very good job."
Toronto traded second baseman Aaron Hill and infielder John McDonald to the Arizona Diamondbacks for second baseman Kelly Johnson. The Blue Jays also recalled catcher Brian Jeroloman from Triple-A Las Vegas. ... Blue Jays right-hander Frank Francisco, who missed Sunday's game at Oakland with a sore right shoulder, threw before the game and was available. ... Lind, who left Saturday's game after being hit on the right wrist by a pitch, went 1 for 4 in his return to the lineup. ... Royals leadoff batter Alex Gordon struck out four times in five at-bats. ... Francouer had his ninth career four-hit game. ... The game was delayed when two fans ran onto the field in the bottom of the seventh.