CINCINNATI -- Going into Tuesday, 22 of the Reds' final 31 games of the season are against clubs currently with .500 or better records. Alas, the A's are not one of those clubs.

Yet, it was Oakland who sent the Reds to a 5-4 defeat at Great American Ball Park -- aided by two home runs for four runs in the top of the seventh inning. Cincinnati's freefall from playoff contention continued as it lost for the eighth time in 11 games for a 63-69 record.

Pressed into an emergency spot start for Cincinnati after Nick Lodolo went on the injured list with a sprained left middle finger, reliever Jakob Junis did the rotation a huge solid.

Junis delivered four perfect innings with three strikeouts while throwing 43 pitches (30 strikes).

"We really didn’t know how many innings he was going to be able to go," Reds manager David Bell said. "To be able to give us four was a good start to the game and allowed us to really kind of set things up to give us a chance to win.”

It was Junis' first big league start since April 2, with the Brewers, and easily his longest outing for the Reds since he was acquired in the July 30 trade with Milwaukee for Frankie Montas. The Reds are also missing Hunter Greene and Andrew Abbott because of recent injuries.

“It’s huge," said Junis, who developed as a starter with the Brewers before a shoulder injury forced him into a bullpen role. "It’s no surprise we’ve been kind of hit with the injury bug lately to the rotation, the pitching staff in general. The brunt of that has fallen on the bullpen and that’s a tough spot to be in. Having done both of those, starting and relieving, I know how tough that can be. To provide some length tonight was awesome."

As he dispatched each of his 12 hitters with relative ease, Junis threw strikes and let Oakland put the ball in play. Two of his strikeouts came against his final two batters -- Brent Rooker and JJ Bleday -- in the top of the fourth inning.

"For Jakob to step up and really show why he’s a good pitcher, no matter what part of the game he’s pitching in, he did a nice job tonight of starting the game," Bell said. "It might be something that continues his next time around.”

The game got away from the bullpen in the top of the seventh after Tony Santillan issued a leadoff walk. Max Schuemann hit a two-out, two-run home run to right field against Santillan on a first pitch. Two batters later against lefty reliever Justin Wilson, Lawrence Butler crushed a two-run homer.

A Zack Gelof solo homer against Casey Legumina gave the A's a 5-1 lead in the eighth inning.

The Reds had the bases loaded with two outs in the bottom of the eighth but only plated one run on Santiago Espinal's four-pitch walk. Against All-Star closer Mason Miller, they rallied for two runs and four hits in the bottom of the ninth inning. But pinch-hitter Amed Rosario struck out to end the game, leaving two runners in scoring position.

That left Cincinnati with a 10-24 record in one-run games -- worst in the National League.

"That’s what I set out to do, eat some innings up and give the guys a chance to win," Junis said. "Unfortunately, it didn’t fall our way.”