Former Padre Tommy Pham was booed heartily by most of the 31,121 in Petco Park when he walked to the plate with two outs in the first.
He responded by ripping left hander Sean Manea’s fastball 424 feet over the left-center field wall.
The rest of the night was spent putting men on base and leaving them there for the Reds — 1 for 8 with runners in scoring position and seven stranded.
Further complicating matters was that Tyler Naquin and Mike Moustakas were on the original lineup card, but both were scratched by the game’s start and Naquin landed on the 10-day injured list.
So the Reds were without regulars Naquin, Moustakas, Jonathan India and Nick Senzel.
The 1-0 lead lasted only two batters into the bottom of the first against Reds left-hander Nick Lodolo, making his second major league start. Austin Nola opened with a single to left and Manny Machado launched one into the left field seats for a quick 2-1 San Diego lead.
The Padres added a run in the fourth when Lodolo walked Jurickson Profar, Jorge Alfaro singled and with two outs Ha-Seong Kim dropped a run-scoring single into center field for a 3-1 lead.
Lodolo left after five innings with a line of thee runs, five hits, two walks and eight strikeouts for his 90-pitch effort.
San Diego pushed its advantage to 4-1 in the seventh against relief pitcher Hunter Strickland. Machado doubled, moved to third on a ground ball and scored on Luke Voit’s sacrifice fly.
After Pham’s home run, the Reds littered the bases with runners, but couldn’t score.
They put their first two on and loaded the bases with two outs in the second, but Kyle Farmer swung at the first pitch and popped up.
Pham came to bat in the third and the crowd booed even louder. He answered with a solid double to left center. And the Reds had two on with two outs, but Alejo Lopez grounded out.
Farmer led off the fifth with a single and Pham came to bat with one out and the crowd’s boos reached a raucous crescendo. He singled for his third hit, putting runners on second and first.
But slump-shrouded Joey Votto (.105) popped out and Tyler Stephenson also popped out.
Pham led off the eighth a triple shy of hitting for the cycle, but he popped up and the crowd let out its loudest roar of the evening.
Votto, struggling so much that he is altering his swing and his stance, followed Pham by grounding out. He had struck out in nine of his previous 11 at bats.
Cincinnati’s offense continues to struggle mightily. It went down in order in the sixth, seventh and eighth. And 13 straight made outs the last four innings and 13 straight made outs until Aristides Aquino (.067) walked on a full count with two outs in the ninth. Jake Fraley flied to left to end it.
The Reds try again Tuesday night to find a path to victory as they send Reiver Sanmartin (0-1, 6.14) against Joe Musgrove (1-0, 1.42).