CINCINNATI -- A hot, humid night with the ball carrying in a hitter-friendly ballpark was never going to be a good matchup for Matthew Boyd. A 329-foot home run by Joey Votto just over the right-field fence, off Nicholas Castellanos' outstretched glove, was Boyd's demise.
Boyd can live with that. It's part of the game at Great American Ball Park. The baserunners he put on ahead of Votto's drive to make it a grand slam were what doomed him in the wake of the Tigers' 9-5 loss to the Reds.
As the old Riverfront Stadium scoreboard graphic used to say, "Walks will haunt."
"Walks kill you," Boyd said. "Fly balls, home runs like that in this park are gonna happen, especially when the wind's blowing out. You expect that sort of stuff to happen, but it's the walks you have control over."
The loss ended the Tigers' five-game winning streak, as well as their quest to reach the .500 mark for the first time since April 9.
Boyd's surprisingly strong start to the season has caught the attention of potential buyers ahead of next month's non-waiver Trade Deadline. Though Tuesday's outing didn't attract a slew of scouts, the matchup of the fly-ball pitcher with a short outfield fence and summer weather was bound to attract attention.
Boyd (4-5) appeared up to the task early, striking out four Reds over the first two innings as hitters chased his slider. Three of those strikeouts, however, came after he fell behind in the count, including a 3-0 count to Adam Duvall after a leadoff single in the second.
"He was throwing pitches where he wanted them," Tigers manager Ron Gardenhire said. "They weren't swinging."
Trouble was lurking, and Boyd sensed it. A leadoff walk to nine-hole batter and Reds speedster Billy Hamilton in the third inning set the rally in motion.
"You never want to walk a guy like that," Boyd said. "He can turn a single into a double really fast. Ideally, make them earn it."
Boyd walked Hamilton and Tucker Barnhart, the latter from an 0-2 count after two missed bunt attempts, with a Jose Peraza single in between. That loaded the bases for Votto, who hadn't homered since May 13 but whose reputation as one of baseball's toughest at-bats is still well-earned.
Boyd fell behind again but threw a 2-1 curveball down in the zone that Votto golfed toward the right-field fence.

"I wanted to let the barrel move a little bit," Boyd said. "When it's off the bat, you don't really think about what's going to happen. I just thought I did what I wanted to on the [pitch]."
Statcast™ gave the ball a one-percent hit probability thanks to a 43-degree launch angle and 93.8-mph exit velocity. Only Justin Verlander entered play Tuesday having induced more balls in play at a 40-plus-degree launch angle than Boyd, who had allowed one hit on 56 such balls this season.
This one carried in a park where it didn't have to carry far. Castellanos made a leaping attempt at it but couldn't get enough of a grasp to keep it in, the ball hitting off his glove instead.
"We play in the biggest ballpark in the league," Castellanos said, referring to Comerica Park. "It is what it is."
It was the first grand slam off Boyd in his Major League career.
Barnhart's RBI double in the fourth completed the damage against Boyd, whose four innings tied his shortest outing of the season. Meanwhile, Reds starter Sal Romano (4-7) scattered baserunners but avoided the big hit over seven scoreless innings for his first win since May 30.

JaCoby Jones' pinch-hit, bases-loaded walk and Leonys Martin's two-run double ignited a five-run Detroit ninth to avoid a shutout.
SOUND SMART
Votto's home run was the 59th homer off Boyd in his Major League career but just the 11th from a left-handed batter and the second this year. Boyd's last two home runs allowed, however, have come from lefty hitters, the first to Andrew Benintendi on a solo shot at Fenway Park on June 7.
UP NEXT
Michael Fulmer (3-5, 4.13 ERA) plans to have at least three jerseys ready to sweat through on a hot Wednesday afternoon as the Tigers wrap up their series with the Reds in a 12:35 p.m. ET game at Great American Ball Park. Fulmer has tossed seven innings of one-run ball in each of his last two outings, pounding the strike zone with sinkers. Tyler Mahle (5-6, 3.96) will start for the Reds.