PHOENIX -- Danny Duffy surrendered a run in each of his first two spring innings, but the Royals slugged their way back to beat the Brewers, 6-3, on Tuesday at Maryvale Baseball Park.
Royals catcher Brayan Pena doubled home two runs in the fourth inning to tie the game, and Ryan O'Hearn homered in the sixth off Brewers right-hander Hiram Burgos for a 3-2 lead. The Royals extended their lead with three more runs against Burgos in the eighth, when Peter O'Brien's two-run homer cleared the 30-foot batter's eye in center field -- O'Brien's third homer this spring.
"He has been fun to watch," Royals manager Ned Yost said of O'Brien. "You see him in batting practice, in games. His power is incredible."
The Royals have won three of their first four Cactus League games.
Duffy, the Royals' likely Opening Day starter, gave up three hits and two runs over 1 2/3 innings in his spring debut. Brewers right fielder Domingo Santana gave the Brewers an early lead with a single to score Keon Broxton, who had led off the bottom of the first inning with a triple. In the second inning, Duffy surrendered a solo homer to Brewers bench candidate Yadiel Rivera that banged off the batter's eye.
Duffy likely will throw once more before leaving March 9 to the join the United States team in the World Baseball Classic.
Right-hander Zach Davies started for Milwaukee after a 22-minute rain delay and worked one scoreless inning with two strikeouts. He would love to start Opening Day, but Brewers manager Craig Counsell has yet to make any announcements.
"I'm going to prepare like it," Davies said.
Royals up next: The Royals will get their first look at right-hander Nathan Karns against the Cubs at 2:05 p.m. CT Wednesday. Karns, acquired from Seattle in the offseason for Jarrod Dyson, is in a battle with Chris Young and Travis Wood for the No. 5 spot in the rotation. Karns will go two innings or 35 pitches.
Brewers up next: Bob Uecker makes his spring debut Wednesday with a radio broadcast of the Brewers-Reds game at 2:05 p.m. CT from Maryvale Baseball Park. Right-hander Chase Anderson is scheduled to make his spring debut against Cincinnati's Losalverto Bonilla.
Adam McCalvy has covered the Brewers for MLB.com since 2001. Follow him on Twitter @AdamMcCalvy, like him on Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.