SAN DIEGO -- It was a gorgeous summer-like Friday night in San Diego, yet a snowball appeared.

Well, a snowball effect, to be more precise.

The Pirates saw fortune turn against them not once, not twice, but numerous times in their 4-3 loss to the Padres in the series opener at Petco Park. A three-run home run by Luke Voit in the sixth inning erased Pittsburgh's hard-fought three-run lead, but the momentum had already shifted toward San Diego as the snowball effect grew.

Instead of a confidence builder to start a six-game road trip against two National League West powers (the Padres and Dodgers), the Pirates must shake off one that got away.

¡°That was a great battle,¡± Bucs starting pitcher Jos¨¦ Quintana said. ¡°It¡¯s tough to get a loss like that, but we competed pretty good. We¡¯re fighting a tough team, a great lineup. I think we showed something on the field. If we can play like that, we¡¯re going to get a lot of 'W¡¯s'¡±

The snowball sequence:

? The Pirates began the game short-handed at first base after Yoshi Tsutsugo landed on the 10-day injured list because of a lumbar muscle strain.

? Michael Chavis, the de facto first baseman, experienced left forearm discomfort after a swing-and-miss in the fourth inning. Chavis, hit by a pitch on that arm against the Rockies on Wednesday, came out of the game in favor of pinch-hitter Tucupita Marcano in the sixth. Bucs manager Derek Shelton said Chavis is day to day.

? Josh VanMeter shifted from second base to first upon Chavis¡¯ departure, the first time he has appeared at the position this year. (VanMeter had 11 Major League starts and 96 innings of experience at the position over three previous seasons.)

? In his first half-inning subbing for Chavis, the ball found VanMeter. With one out and Pittsburgh ahead, 3-0, VanMeter had a brief lapse in concentration and was not on the bag when a throw from catcher Tyler Heineman beat Eric Hosmer, who had hit a ball a short way up the third-base line. VanMeter was charged with an error.

? That ended Quintana¡¯s night with a shutout still intact for the left-hander, but two right-handed-hitting power threats were due up.

? Reliever Wil Crowe retired Wil Myers on a flyout that would have been the final out of the inning, but instead, the Padres had an extra out to work with. Voit capitalized by pulling a 2-2 slider into the left-center-field stands, tying the game at 3.

The Pirates¡¯ win probability dropped from 85 percent to 48 after Voit¡¯s swing, per Statcast. The Padres got the run they needed to seal it in the eighth inning on an RBI single by Myers.

¡°That old clich¨¦ that one play doesn¡¯t lose you a game, but man, this sure feels like it,¡± VanMeter said. ¡°That¡¯s a play that¡¯s got to be made, whether I¡¯ve played over there or not. That sucks.

¡°I got lost watching the play and didn¡¯t find the bag. Make a mental mistake, and good teams capitalize on it.¡±

It¡¯s a Catch-22 for a player like VanMeter. He brings value with his ability to plug holes as needed, but it means routine plays can become anything but. Before appearing at first base on Friday, VanMeter had seen time this season at second base (24 starts), right field (two innings), catcher (one inning) and pitcher (one inning). He also has seen time in left field and at third base during his career.

¡°It¡¯s a tough situation,¡± Shelton said. ¡°We lost Chavis during the game, and [VanMeter] just got behind the bag.¡±

Added VanMeter: ¡°I think I make that play 10 times out of 10, 99 times out of 100. That happened to be the one time. ¡­ Terrible feeling, but the good thing about baseball is there¡¯s another one tomorrow, and I can make up for it tomorrow.¡±