Chen picked up the Royals' beleaguered rotation with seven solid innings, pitching Kansas City past the Detroit Tigers 5-2 Sunday.
Chen (7-2), who moved into the rotation on July 12 after 19 relief appearances, limited the AL Central leaders to five hits and two runs. He earned the first victory for a Royals starter on their seven-game homestand.
"I was pounding the strike zone, mixing in all my pitches, throwing different angles," Chen said.
Eric Hosmer had three hits, including a three-run homer in the fifth inning.
The Royals stayed close in the wild-card chase, taking the final two games of the series after losing 16-2 Friday.
"After that game, it was a bad feeling," Hosmer said. "They just flat out beat us that day. Just to forget it as a team and bounce back like that shows a lot about the character on the team and pitching staff."
The Kansas City starters had an 8.00 ERA in the first six games of the homestand, allowing 24 runs on 41 hits and 16 walks in 27 innings. The other four starters had a 9.43 ERA in that span and had failed to make it beyond 4 1/3 innings in four starts.
Fister (12-8) allowed five runs on eight hits in 6 1/3 innings.
Chen kept the Tigers hitters off-balance all afternoon.
"We hit a lot of lazy fly balls," Tigers manager Jim Leyland said. "The credit goes to Chen. He changes speeds and got us out in front a lot. You know what you're going to get with him. He changed speeds and got us out in front and mixed his pitches. He was very effective."
Greg Holland allowed Prince Fielder's double with two out in the ninth, but collected his 40th save in 43 chances. Joakim Soria, Jeff Montgomery and Dan Quisenberry are the only other Royals relievers to earn 40 saves in a season.
"Chen pitched how he always pitches," Avila said. "You can look back at any game he's pitched and it's always the same. He mixes a lot of pitches, works in and out, changes speeds, and never gives in.
"After he gets you out, you go back to the dugout saying, 'Man, how did I get out?'"
Iglesias hit his second home run since the Tigers acquired him in a July 30 trade with Boston.
"After that pitch, Chen was locked in the entire day," Hosmer said. "We knew if could get a lead and hand it off to the bullpen, we'd be in a good spot."
The Royals got a run in the fourth when Billy Butler grounded a single.
Jarrod Dyson led off the Royals' seventh with a triple into the left-field corner and scored when Gordon dunked a fly ball into shallow right over a drawn-in Tigers infield for a single.
This time Cabrera hit a comebacker and Chen threw out Jackson at third. Chen fell behind 3-0 to Fielder, who then looked at the next three pitches -- all strikes.
"It was a huge play with Miguel," Chen said. "We have a two-run lead and the first pitch, he hits a groundball to me."
Fielder played in his 486th consecutive game, the longest active streak in the majors. ... C Salvador Perez, who hit a two-run homer Saturday night, was not in the Royals' lineup Sunday. Manager Ned Yost said he decided to rest Perez with temperatures reaching 100 degrees and the Royals in a stretch of 44 games in 44 days. ... Leyland said OF Nick Castellanos would start again Monday after making his first major league start Saturday. "He's got a feel for hitting," Leyland said. "He's a confident kid in the batter's box. He looks natural in the batter's box."