CINCINNATI -- As the game went one with no hint that either team was capable of scoring, Arizona catcher Miguel Montero became philosophical.
"I knew eventually it was going to go one way or the other," he said.
But whenever it goes really long, the Diamondbacks win. Arizona is 13-0 all-time in games of at least 15 innings.
"You get into a game like this, everybody is trying to end it," manager Kirk Gibson said. "You tell yourself not to do it, but that's the reality of it."
Ahmed's single off J.J. Hoover (1-8) gave the Reds their ninth loss in 10 games since the All-Star break, a slump that has dropped them below .500 for the first time since June 21. The offense has been the problem -- they've scored only 17 runs in those 10 games, by far the fewest in the majors.
"Just nothing was falling in for either team, really," Ahmed said.
Cincinnati's Aroldis Chapman fanned the side in the ninth and extended his major league record for a reliever to 44 consecutive games with at least one strikeout. One of his pitches was clocked at 104 mph. Devin Mesoraco led off the second with his 17th homer off rookie Chase Anderson, which ended a streak of three straight games at Great American without a homer -- the longest in the ballpark's 12 seasons. Montero singled home the tying run in the fourth off Homer Bailey, who gave up five hits in eight innings.
Anderson allowed three hits and matched his career high with eight strikeouts in seven innings. He retired the last 11 batters he faced. Arizona right fielder David Peralta saved a run in the fourth with a diving, backhand catch of Brayan Pena's fly ball. He doubled up Chris Heisey at first base.
Reds manager Bryan Price batted Jay Bruce second in hopes of getting his lineup out of a slump. Bruce went 0-for-4 with three strikeouts and a pair of walks.
Many of the 30,288 fans flashed their cell phone camera lights during extra innings and did the wave to amuse themselves.
Reds reliever Jumbo Diaz faced Mark Trumbo in the 12th and gave up a single that ended a streak of 14 consecutive Diamondbacks retired. ... Arizona's Martin Prado went 0-for-5, which ended his six-game hitting streak. ... Mesoraco's 17 homers are the most by a Reds catcher since David Ross hit 17 in 2007. ... Zack Cozart extended his slump to 0-for-22, which matched his career high from the start of this season. ... Chapman has struck out the side nine times this season. ... Todd Frazier struck out four times. The Diamondbacks struck out a season-high 18 in all.