BOSTON (AP) - Kansas City Royals manager Ned Yost and catcher Salvador Perez can both see the confidence growing in Yordano Ventura.
The 24-year-old right-hander can feel it, too.
Ventura pitched six effective innings, helping the AL Central-leading Royals beat the Red Sox 6-3 on Saturday night, ending Boston's four-game winning streak.
''It looks like to me he's getting his swagger back a little bit,'' Yost said. ''He's competing hard out there.''
Perez hit a three-run homer, Kendrys Morales added a two-run double and Alex Rios had three singles and an RBI for Kansas City.
Following losses the first two nights, the Royals can earn a split of the four-game series Sunday.
Ventura (8-7) gave up one run and six hits, striking out six. He improved to 4-0 in his last six starts.
''For him, like it is for anybody, it's a confidence-type of thing,'' Perez said.
Ventura said through an interpreter that ''he has that same confidence that he had for most of last season,.''
He went 14-10 with a 3.20 ERA in helping the Royals to the AL title last season.
Mookie Betts hit a solo homer and David Ortiz had two singles and three walks for the Red Sox. Boston had won four of the five meetings this season, and 10 of 12 since the start of 2014.
''I think Ventura did a good job of really bearing down when we had men in scoring position,'' Boston interim manager Torey Lovullo said. ''I know we left a number of men on base in critical moments. We just couldn't get the big hit tonight.''
Greg Holland got Travis Shaw to pop out with the bases loaded for the final out, earning his 28th save.
Leading 2-0 in the sixth, the Royals chased Matt Barnes (3-4) when Perez homered.
Morales lined his double off the Green Monster in the first inning.
Ventura stranded five runners in the first four innings before Boston scored on Shaw's groundout in the sixth. Betts homered over the Monster off Ryan Madson.
Making just his second major league start, Barnes gave up five runs and eight hits in 5 1-3 innings.
''I thought I made a pretty good pitch, (Morales) put a pretty good swing on it,'' Barnes said. ''And then again to Perez, just trying to go away from him, expand off and it wasn't a bad pitch, it was a little up. But he had a pretty good swing on it.''
Royals: OF Alex Gordon is set to start a rehab assignment with Triple-A Omaha on Sunday. He's been on the DL since early July with a strained groin. ... C Perez took a foul ball off the mask and was shaken up, but stayed in the game. After the game he showed his lip and said: ''it's part of the job.''
Red Sox: Utility player Brock Holt was in the original lineup, but was scratched with a strained left oblique after batting practice. ... Ortiz fouled a ball off his right foot in his first at-bat, and limped a bit. ... Lovullo said RHP Rick Porcello (soreness, right triceps) could return on the upcoming trip after he said he ''felt great'' at the end of a rehab start for Triple-A Pawtucket on Friday.
Royals 2B Omar Infante singled to end an 0-for-31 skid.
ANOTHER NICE GRAB
Boston's Jackie Bradley Jr. made a leaping grab at the wall in right field. On Friday, he made a diving catch in left.
Royals: RHP Edinson Volquez (11-7) is scheduled to make his team-leading 26th start in the series finale. He's held hitters to a .178 average with runners in scoring position, second-best in the AL.
Red Sox: LHP Eduardo Rodriguez (7-5) is looking to follow his solid outing earlier this week. The 22-year-old rookie pitched eight innings of one-run ball, earning the win against Cleveland on Tuesday.