SAN DIEGO (Interstat) — Carlos Cortes launched a solo home run in the first inning and the Athletics added two runs in the second, staking the visitors to an early lead they never relinquished in a 5-2 victory over the Padres before 41,799 at PETCO Park on Sunday evening.

The Athletics improved to 27-26 with the win, snapping a two-game losing streak in the process. The Padres, who had won the first two games of the series, dropped to 31-21.

Athletics left-hander Jacob Lopez earned his fourth win of the season, scattering nine hits over six innings while striking out four and walking two. He allowed two earned runs, both coming on solo scores in the sixth and seventh innings. Scott Barlow pitched a scoreless ninth inning to pick up his first save, retiring the side after the Padres put two runners on base with no outs.

Padres starter Michael King took the loss, falling to 4-3. He lasted only 3 2/3 innings, surrendering four earned runs on five hits with four strikeouts and four walks.

The Athletics opened the scoring in the top of the first when Cortes, the right fielder, drove a 2-1 pitch over the right-center field wall for his fifth home run of the season. After Nick Kurtz struck out, Shea Langeliers popped out and Tyler Soderstrom grounded out to end the inning.

The Athletics doubled their lead in the second. Jonah Heim led off by striking out, but Zack Gelof drew a walk. Jeff McNeil flied out to right, but Henry Bolte laced a double to left-center, scoring Gelof. Alika Williams followed with a single to left, plating Bolte to make it 3-0. Williams was then caught stealing second to end the inning.

Padres hitters struggled to solve Lopez early. Fernando Tatis Jr. singled to lead off the bottom of the first, but Miguel Andujar grounded into a double play and Gavin Sheets struck out. In the second, Xander Bogaerts reached on an infield single and advanced to second on a throwing error by third baseman Gelof, but Jackson Merrill and Ramon Laureano lined out. Tatis singled again in the third but was thrown out trying to stretch it into a double by left fielder Soderstrom.

The Athletics added a run in the fourth, again capitalizing on walks. Heim led off with a double, Gelof struck out, and McNeil walked. Bolte walked to load the bases, but Williams struck out. Cortes then walked to force in Heim, making it 4-0. Kurtz struck out to leave the bases loaded.

King was lifted after issuing that walk to Cortes. Reliever Ron Marinaccio finished the inning and worked a scoreless fifth, but the Athletics’ bullpen held the Padres at bay until the middle innings.

Lopez cruised through the fifth, allowing only a single to Ty France and a double to Tatis that ended with France being thrown out at the plate. In the sixth, the Padres finally broke through. Andujar doubled to left, moved to third on a groundout by Sheets, and scored on a sacrifice fly by Manny Machado. Bogaerts singled, but Merrill grounded out to end the inning, leaving the score 4-1.

The Padres crept closer in the seventh. After Lopez had retired the first two batters of the inning, France crushed a 1-1 pitch to right field for his fifth home run of the season, cutting the deficit to 4-2. Rodolfo Duran popped out, and Tatis grounded out.

The Athletics answered immediately in the top of the ninth, adding an insurance run that proved critical. Reliever Bradgley Rodriguez, who had worked a perfect eighth, began the ninth by allowing a single to Cortes. Pinch-runner Lawrence Butler replaced Cortes, and Kurtz bunted for a single, moving Butler to second. Langeliers struck out, but Soderstrom singled to right, scoring Butler and sending Kurtz to third. Heim walked to load the bases, but Gelof and McNeil both struck out to end the inning, leaving the score 5-2.

Barlow, the Athletics closer, came on for the bottom of the ninth with a three-run lead. He immediately ran into trouble. Merrill challenged a called third strike, and the call was overturned, resulting in a walk. Laureano also walked, putting runners on first and second with no outs. France struck out swinging, and pinch-hitter Nick Castellanos struck out looking. Tatis then flied out to right fielder Butler, ending the game and giving Barlow his first save.

Key performances for the Padres included France’s home run and a 2-for-3 afternoon from Bogaerts, though the middle of the order struggled — Merrill, Laureano and Duran each went 0-for-3. For the Athletics, Cortes finished 1-for-3 with a home run and two walks. Bolte doubled and drove in a run, and Williams had a hit and an RBI.

The Athletics avoided a three-game sweep after losing the first two games of the series by scores of 7-3 and 2-0. They return home to face the Seattle Mariners on Monday for a three-game series. The Padres host the Philadelphia Phillies starting Monday.

Interstat’s game simulator had projected a final score of Padres 6, Athletics 5, and the ELO system gave San Diego a 61.60 percent probability of winning. The Padres were installed as a pregame favorite with a spread of minus-1.5. The combined total of seven runs went over the over-under line of eight.