SAN DIEGO _ The Padres continued to get on base, but they couldn't turn those runners into runs.
And near the end of a futile and frustrating day, one of their new relievers faltered. Then their most reliable reliever did, too.
The Diamondbacks scored two runs off Padres closer Kirby Yates to break a ninth-inning tie and hand the Padres their first loss in three games this season, 4-3 Sunday at Petco Park.
The home team's chance to be 3-0 for the first time since 1984 and also the major leagues' only undefeated team this season crumbled when the Diamondbacks scored two runs off Emilio Pagan in the eighth inning and the pair off Yates.
Two days after he drove in six runs and a day after he went home before the game with what the team called a "stomach issue," Eric Hosmer hit a 409-foot home run over the wall in center field in the third inning to give the Padres a 1-0 lead.
Greg Garcia's pinch-hit single in the eighth inning, one of only two Padres hits in 12 at-bats with a runner in scoring position, tied the game 2-2.
That was the entirety of the tangible portion of the Padres' offense.
They entered the game having reached base at a .379 clip the first two games of the season.
Wearing their new green Sunday camouflage uniforms, they managed just six hits but walked nine times to continue to give themselves opportunity and tax the Diamondbacks' pitching staff.
The Padres ran Diamondbacks starter Zac Gallen after four innings. As a rookie, Gallen had shut them out on one hit over seven innings last September.
He threw 88 pitches Sunday. That came a day after Robbie Ray threw 97 pitches in his 3 2/3 innings.
The Padres, who had walked 14 times and worked 28 full counts in the first two games, added nine full counts Sunday.
According to the Elias Sports Bureau, which has only tracked counts since 2000, that is eight more full counts than the Padres' previous high in any three-game stretch this millennium .
But they couldn't make it all add up as they had the season's first two games, when they won 7-2 and 5-1.
The Padres stranded runners in scoring position in five innings, including the one in which they slid their way out of a scoring opportunity.
Three walks in the first inning _ by Trent Grisham, Tommy Pham and Hosmer _ went for naught when Wil Myers chopped the first pitch he saw to third baseman Eduardo Escobar, who took three loping strides and stepped on the bag to end the inning.
To start the bottom of the seventh, Josh Naylor reached base when Arizona second baseman Ketel Marte bobbled a grounder.
With Fernando Tatis Jr. up, Diamonbacks reliever Kevin Ginkel (El Capitan High, Southwestern College) bounced a pitch in front of the plate that catcher Carson Kelly blocked and threw wide of second as Naylor slid over and past the base. Easily safe, he was tagged out by shortstop Nick Ahmed before getting his foot back to the bag.
Tatis lined the next pitch into right field, an ultimately harmless single.
After Grisham struck out, the Diamondbacks intentionally walked Manny Machado to bring up Pham, who flied out to right field.
That made the Padres 0-for-7 with runners in scoring position.
Pagan, acquired just before spring training in a trade that sent center fielder Manuel Margot to Tampa Bay, came on for the eighth inning to face the top of Arizona's order.
Ketel Marte began the inning with a walk and went to second on David Peralta's single. Starling Marte then reached out and slapped a 1-2 fastball on the ground down the right field line, past Hosmer, who was playing off the line.
Staling Marte scored, and Peralta went to third on the hit, and Peralta scored on a double play grounder by Eduardo Escobar. Hosmer made a diving stop to his right to end the inning.
The Padres got back to doing their walking thing, and this time they were able to eek a run.
Hosmer and Myers walked to start the bottom of the eighth. Jurickson Profar's fly ball moved Jake Cronenworth, making his major league debut as a pinch runner for Hosmer at second, to third base.
That brought in Diamondbacks closer Archie Bradley and brought up pinch-hitter Garcia.
Garcia, who last season had a .370 on-base percentage against right-handers, fouled off a fastball before poking a change-up into center field to tie the game.
Yates came on in the ninth, a day after pitching that same inning with a four-run lead.
This one didn't go well, as he was not his usual kind of sharp. Ildemaro Vargas hit a one-out single, which was followed by Kevin Cron and Nick Ahmed working their 3-2 walks to load the bases.
A sacrifice fly by Ketel Marte gave the Diamondbacks a 3-2 lead, and Peralta drove home pinch-runner Tim Locastro with a single.
It was one last failure with a runner in scoring position that ended the game.
After Grisham led off the bottom of the ninth with a single and Machado struck out and Pham was the victim of a spectacular catch by Peralta in deep left, Cronenworth doubled to right to score Grisham, who had moved to second uncontested.
But Myers sent a grounder back to Bradley to end the game.
