PHOENIX -- Right-hander Tyson Ross' slight if undisclosed mechanical adjustment seemed to make a substantial difference on Saturday night.

"It allowed me to execute a lot more pitches and get ahead of guys and put them away," said Ross, who tweaked his delivery during his last bullpen session.

Ross pitched the San Diego Padres' first complete game of the season, giving up four hits and tying a season high with nine strikeouts in an 8-1 victory over the Arizona Diamondbacks at Chase Field.

"I was just trying to attack hitters," Ross said. "I put an emphasis on getting the leadoff guy out and make them put the ball in play. I've had some trouble with command and walking guys. I just really wanted to challenge people tonight."

Ross (4-7) halted a three-game losing streak and also had his first career triple, driving in the second run in a four-run ninth inning that put the game away.

He threw 111 pitches in his first complete game since Aug. 21, 2014, a 2-1 loss at the Los Angeles Dodgers. He threw a 3-0 shutout against Cincinnati on July 2.

"Nobody in the league wants to face him. He's filthy," San Diego interim manager Pat Murphy said.

Shortstop Clint Barmes had three hits and two RBIs and first baseman Derek Norris and center fielder Melvin Upton Jr. homered for the Padres (34-37), who had lost four of six. They are 2-3 under Murphy.

Barmes singled in a run in the second inning and Norris, making his second career start at first base, hit his ninth homer of the season for a 2-0 lead in the third. Barmes doubled in a run in the sixth and doubled to open the ninth.

"Forty is not a death wish," Murphy said of Barmes, who is 36. "He's a mature player and he plays winning baseball."

Upton hit his first home run of the year to cap the four-run ninth.

Arizona broke Ross' shutout in the seventh inning, when second baseman Chris Owings tripled with two outs and scored on catcher Welington Castillo's double.

"When his slider is on, it is hard to recognize," Hale said of Ross. "You try to get guys to lay off the ball down low because it is going to break out of the zone, but he was really good tonight. He controlled the game from the first pitch on."

The Diamondbacks (33-35) failed in their ninth attempt since April 26 to get back to .500.

Left-hander Robbie Ray (2-2) gave up six hits and four runs (three earned) in 5 2/3 innings. He struck out a career-high seven and walked two.

"I just made a few mistakes and they took advantage of it," said Ray, who had given up three runs in his precious four starts.

Right fielder Matt Kemp had two hits and scored twice for the Padres.

Arizona first baseman Paul Goldschmidt singled and walked. He leads the majors with a .358 batting average.

NOTES: Arizona traded RHP Touki Toussaint, its first-round pick in the 2014 draft, and RHP Bronson Arroyo to Atlanta for 2B Phil Gosselin during the game. Toussaint is 2-2 with a 3.69 ERA at low Class A Kane County. Arroyo, 38, has not pitched since undergoing Tommy John surgery on July 18, 2014. Atlanta will pick up the remainder of the about $10 million guaranteed to Arroyo, who is to earn $9.5 million this year and has a $4.5 million buyout on a $11 million option for 2016. Gosselin hit .325 in 20 games with Atlanta this season but is expected to miss about another month while on the disabled list with a fractured thumb. ... Arizona RF Yasmany Tomas did not start but flied out as a pinch hitter. He suffered a left elbow contusion when he was hit by a pitch in the first inning on Friday and was removed in the fourth inning. Rookie Danny Dorn started in right field, the first outfield start of his career. ... San Diego C Derek Norris made his second start of the season at first base in order to get his bat into the lineup against Arizona LHP Robbie Ray. Norris' 27 extra-base hits lead major league catchers. ... San Diego RHP Tyson Ross' ERA dropped before the game started when a scoring change on a June 10 play at Atlanta took away and earned run and dropped his ERA to 3.90. Padres RHP Andrew Cashner also had two earned runs removed after a scoring change from a June 11 game at Atlanta, lowering his ERA to 4.24. ... Padres CF Melvin Upton batted leadoff for the third time in his last four games, all since interim manager Pat Murphy has been in place.