Hector Neris jogged from the bullpen to the mound at Citizens Bank Park as Survivor's "Eye of the Tiger" filled a half-empty ballpark.

Sunday's game slogged toward its fourth hour. But Neris carried confidence in his splitter because when he last pitched, Thursday, he threw the pitch 15 times and generated six swings and misses. It is a devastating pitch that transformed him from nondescript middle reliever into the Phillies' closer.

Within 10 pitches of Sunday's 5-4 loss, a one-run lead had evaporated. In the ninth inning, Neris threw his splitter eight times. The Diamondbacks did not whiff at it once. Neris walked the No. 8 hitter and allowed two ground-ball singles on splitters, and the path to another Phillies loss was paved.

Neris, 28, has not resembled the same pitcher from a season ago. He is the Phillies closer because he is the one reliever with a potential to be here when the wins are more frequent than the losses, so this is a chance to learn about how Neris can handle pressure.

The results are inconsistent because his splitter is inconsistent.

"I don't know," catcher Cameron Rupp said. "I think a lot of us are scratching our heads about it. It hasn't been the same pitch for him this year. He knows it, I'm sure. It's no secret."

The Phillies have lost 46 games, and 17 of those were by one run. No other team in baseball has suffered more than 13 one-run losses.

The bullpen is to blame for quite a few of those defeats. Neris' scattered ninth cost rookie Ben Lively a win. Then, in the 10th inning, Rey Fuentes crushed Jeanmar Gomez for his first big-league homer. Gomez, so steady as the closer last season while Neris posted zeroes in the eighth inning, has a 7.20 ERA. His job in the bullpen could be in peril.

The Phillies have blown 12 of their 22 save chances. That 45 percent success rate is worst in the majors. The league average is 64 percent.

There is a twinge of irony: The Phillies' likeliest all-star representative is Pat Neshek. He pitched a scoreless seventh inning against the top of Arizona's lineup. His ERA is 0.67. He has thrived as a setup man, and both team and pitcher are happy to have him in that role.

For now, they will test Neris with more ninth-inning assignments.

"His split is hot and cold," Phillies manager Pete Mackanin said. "For every two good ones he throws, he throws two bad ones. It's hard to figure out what he's doing. He walked that leadoff hitter and that's the guy that scored. He's tough to figure out."

Neris said he could not control the fact that the two grounders found holes and became singles. But he could control the leadoff walk to Nick Ahmed on five pitches.

"I'm making my pitches the same every time I go to the mound," Neris said. He added: "I enjoy it, no matter whether it's closer, the eighth or the seventh. I go into the game trying to save every inning to help my team win."

Sometimes, the Phillies are permitted nice things. They had hope Sunday for eight innings. They pelted Robbie Ray - one of the game's top lefties and unhittable for the last month - for four runs.

Ray, before Sunday, had pitched to a 0.27 ERA in his previous five starts. Opponents had batted .115 against him, with a third of them striking out, in that span. He had permitted one home run in his last 37 innings.

He surrendered two within the first five batters he saw Sunday.

Ray tried to blow a 97-mph fastball past Aaron Altherr in the first inning. Altherr turned on the 2-2 pitch for his team-leading 12th homer. An inning later, Maikel Franco attacked a first-pitch, elevated fastball. He did not try to pull the pitch. He smashed it to the opposite field for a solo homer.

Franco added two walks Sunday. He now leads the Phillies with 21 walks. He also leads the majors in double plays, with 13.

Franco batted with two outs in the ninth and the winning run on second base. He fought Diamondbacks reliever Archie Bradley for 10 pitches. Bradley fired a 97-mph fastball that Franco skied to third base.

"That," Mackanin said, "was a tough loss."