"I thought he threw the ball well. Again, I thought we saw his fastball command improve and a good slider," Padres manager Bud Black said. "He's doing his part to forge his way onto our roster."
"[It's] progress every time out. Getting into more season-like situations, getting up-and-down six times today was huge, getting the pitch-count up," Ross said. "Everything is progressing the way it should.
"I'm not worried where I'll end up when the season breaks, but personally I feel great. Feeling strong, throwing the ball well."
Arizona pitcher Ian Kennedy, who hadn't allowed an earned run all spring, didn't fare nearly as well, as he allowed four runs on four hits in 3 2/3 innings.
Kennedy walked one and struck out one and left during the fourth inning when he was hit below his left knee by a one-hop smash up the middle off the bat of Jedd Gyorko. Kennedy was diagnosed with a contusion below his left knee.
Left fielder Kyle Gaedele smashed a grand slam to center in the Padres' five-run seventh, breaking the game wide open.
The D-backs got two hits from Gerardo Parra, including his third home run of the spring. Parra reached base three times.
The Padres got a two-run home run from Yonder Alonso and leadoff hitter Alexi Amarista had two hits. Teammate Jesus Guzman followed Alonso's home run with one of his own in the fourth inning.
Alonso later added a double in the sixth inning. Guzman followed with an RBI double.
The D-backs scored five runs in the ninth inning, three coming home on a home run from designated hitter Didi Gregorius.
Padres up next: The Padres have split-squad games set for Sunday. The team will travel to Tempe, Ariz., for a game against the Angels at 1:05 p.m. Rotation hopeful Freddy Garcia will look to bolster his chances by going five or six innings. Garcia was very good in his last outing, striking out six over four innings. It was his best start of the spring. Also Sunday, the Padres will head to Tucson to face the D-backs, also at 1:05 p.m. Sean O'Sullivan and Thad Weber will each throw in upwards of three innings in that game.
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter.
This story was not subject to the approval of Major League Baseball or its clubs.