SAN DIEGO (Interstat) — Brandon Pfaadt pitched five scoreless innings and Max Kepler belted a three-run homer, leading the Arizona Diamondbacks to an 8-0 victory over the San Diego Padres on Monday night at PETCO Park.

The Diamondbacks jumped on starter Walker Buehler early, plating two runs in the first inning. Ketel Marte led off with a triple to center field, and after Geraldo Perdomo was hit by a pitch, Corbin Carroll struck out. Gabriel Moreno walked to load the bases, and Lourdes Gurriel Jr. flew out to left. Kepler then lined a single to left, scoring Perdomo and moving Moreno to third. The ball was misplayed by left fielder Samad Taylor, allowing Kepler to take second. Nolan Arenado grounded out to end the inning, but Arizona held a 2-0 lead.

Arizona broke the game open in the third inning. After Perdomo lined out, Carroll doubled to left and Moreno singled to left, putting runners at the corners. Gurriel singled to right, scoring Carroll and sending Moreno to second. Kepler then launched his first home run of the season to right field, clearing the bases and extending the lead to 6-0. Arenado struck out and Ildemaro Vargas grounded out, but the damage was done.

Pfaadt, who earned his second win of the season, worked efficiently through the early innings. He retired the side in order in the first, allowed a single to Jake Cronenworth in the second but got a double play, and worked around a Cronenworth single in the third. He struck out six over five innings, allowing four hits and no runs. His previous start had been a win against San Francisco on June 30, and he carried that momentum into Monday’s outing.

Arizona added a solo run in the fourth when Perdomo homered to right field, his sixth of the year. The score became 7-0. Buehler, who took the loss and fell to 5-5, allowed seven earned runs on seven hits over five innings. He struck out four but was tagged for the big third inning and the Perdomo homer. The Padres’ bullpen provided some stability, with Alek Jacob throwing three innings of two-hit, one-run ball and Ron Marinaccio tossing a scoreless inning, but the deficit was already too great.

Nolan Arenado made it 8-0 in the sixth inning with a solo home run to left field, his 10th of the season. That capped the scoring for Arizona, which finished with 11 hits. Kepler went 2-for-4 with four RBIs, Perdomo was 2-for-4 with a homer and an RBI, and Marte, Moreno and Gurriel each had one hit. Arenado also had a hit, a home run and an RBI.

San Diego managed eight hits but could not push a run across. Cronenworth had two singles, Manny Machado singled, Gavin Sheets singled, Ty France singled, Jackson Merrill singled, and Samad Taylor singled. The Padres left seven runners on base and struck out 14 times. Pfaadt was supported by a strong bullpen: Ryan Thompson threw two scoreless innings, striking out four, and Drey Jameson closed with two scoreless innings, allowing two hits and striking out one. The three Arizona pitchers combined for 19 strikes, 53 balls and 19 balls in play, while San Diego pitchers had 17 strikes, 32 balls and 17 balls in play.

The game lasted 2 hours, 25 minutes in front of an announced crowd of 38,204. Arizona improved to 45-45 with the win, moving to .500 for the season. The Diamondbacks had lost their previous game Sunday to Milwaukee, 3-2, and had won two of their last three. San Diego fell to 44-46, having lost three of their last four after a 5-2 win at Los Angeles on Sunday.

The Diamondbacks now have a chance to build on this momentum in the remaining three games of this series at PETCO Park. They travel to Los Angeles for a three-game set beginning Friday before returning home to face St. Louis after the All-Star break. The Padres, meanwhile, host Arizona for two more games before the break, then welcome the Toronto Blue Jays for a weekend series and then hit the road for games at Kansas City and Atlanta.

The most pivotal stretch of Monday’s game came in the third inning when Arizona sent seven men to the plate and scored four runs. Kepler’s three-run homer turned a two-run lead into a six-run cushion, effectively putting the game out of reach and allowing Pfaadt to pitch with comfort. That inning also chased Buehler’s confidence, as he allowed a double, two singles and the home run before recording the final two outs of the frame.

Interstat’s game simulator had projected a final score of Arizona 4, San Diego 3. Interstat’s ELO system gave the Padres a 55.70 percent probability to win. Arizona was installed as a pregame favorite with a spread of minus 1.5. The total score of 8 went over the over/under line of 9.