SAN DIEGO -- The Blue Jays had a chance to secure their first series sweep of the season on Sunday. Instead, they frittered it away with a litany of mistakes.

Trevor Richards walked in the go-ahead run with the bases loaded, Danny Jansen committed a critical catcher’s interference and the Blue Jays fell to the Padres, 6-3, in a sloppy series finale at Petco Park.

The Blue Jays have won each of their last four series but have yet to record a sweep.

“Miscues are going to happen,” Blue Jays manager John Schneider said. “I thought [Richards] was around the zone enough and wasn't getting some calls. I think [Jansen] was trying to help him out there on the catcher’s interference. I mean, miscues happen.”

The mistakes began almost immediately for the Blue Jays. In the bottom of the first inning, George Springer allowed Manny Machado’s ground ball into right field to skip by him and roll all the way to the warning track, allowing Jake Cronenworth to motor around the bases from first and give the Padres an early lead.

In the sixth, with the score tied, 2-2, Richards walked Luis Campusano with the bases loaded and two outs to force home the go-ahead run. The very next batter, Jansen committed catcher’s interference on Tyler Wade to bring another run home.

In the eighth, Nate Pearson issued another bases-loaded walk to force home another run after the Blue Jays had cut their deficit to one.

In all, the Blue Jays issued nine walks, hit a batter and made two errors including the catcher’s interference. They additionally managed just five hits in seven innings against Padres right-hander Joe Musgrove, who entered the day allowing a .337 batting average against.

“I think it was more the walks today than anything,” Schneider said. “And just not getting a big hit when we did have a chance. Give credit to Joe. He threw a good game. We kind of just missed some pitches.”

Davis Schneider hit a solo homer off Musgrove in the second inning and Ernie Clement added a solo shot in the third to pace the offense.

Clement’s homer was particularly notable. He went up and hammered a 90.7 mph fastball well above the strike zone into the second deck of the Western Metal Supply Co. Building for his second long ball of the season. The pitch he hit was 4.18 feet above the ground, the second-highest pitch hit for a home run in the Majors this year, according to Statcast.

“[Musgrove] was throwing a bunch of curveballs and sliders down and away, so I was just trying to get him up,” Clement said. “He definitely threw it up. I don't know really how I got to that. I just kind of reacted to it and I put a good swing on it.”

Xander Bogaerts tied the score with a solo homer in the fourth off Chris Bassitt. Bassitt wriggled out of a bases-loaded, one-out jam in the fifth when Schneider snagged Fernando Tatis Jr.’s line drive and stepped on second base for an inning-ending double play, but the Padres loaded the bases again in the sixth to set the stage for Richards’ and Jansen’s critical mishaps.

Bassitt battled his command throughout and finished with 5 1/3 innings pitched, six hits and four runs (three earned) allowed, three walks and four strikeouts to take the loss. He noted after the game that he’s one of many Blue Jays players battling illness and tried unsuccessfully to pitch through it.

“I just didn't have it today,” Bassitt said. “I didn't feel good and didn't have it today.

“We got about 20 guys on our team sick. I'm one of them, unfortunately. We're passing around a sinus infection, which is not fun.”

It wasn’t all bad for the Blue Jays. Bassitt picked off Jurickson Profar at second base with a pristine move to end the first inning and escape an early jam. Schneider’s leaping grab of Tatis’ liner helped them escape the fifth. Just before he walked in the go-ahead run, Richards made a nifty barehanded play on Jackson Merrill’s dribbler in front of the plate and tossed it to Jansen for a forceout to keep the score tied.

But in the end, the Blue Jays’ mistakes were simply too much to overcome.

“Miscues are part of it,” John Schneider said. “You don't want it to be every day. We're a pretty damn good defensive team. I think today was just kind of a hiccup.”