PHOENIX -- Down two runs but with two on and no one out in the sixth inning Sunday, the D-backs looked poised to at least slim their deficit, if not completely erase it.
The hopeful feelings grew even larger as Justin Upton and Paul Goldschmidt got huge jumps and broke free for a double steal during Edinson Volquez's delivery. But with one swing of the bat, like much of the club's season to date, all the optimism abruptly faded into disappointment.
Miguel Montero drilled a sharp line drive directly at right fielder Mark Kotsay, starting an unlikely and demoralizing double play, effectively ending the D-backs' rally as they eventually fell, 5-4, to the Padres.
"We knew we could run on him and [Upton] was trying to make something happen," D-backs manager Kirk Gibson said. "Miggy absolutely crushed the ball right to him. Would we rather just sit back and be complacent? ... I want them to be aggressive and try to make things happen."
If Montero didn't swing, the D-backs likely would've had two runners in scoring position with no outs. If he would've hit the ball a few feet in either direction, it would've scored at least one. Instead, the worst possible outcome of the play left the team reeling.
"That's a tough play for the Diamondbacks," Padres manager Bud Black said. "When that happens, it's tough to react when you are the runner unless you pick the ball up and really sense where the ball is going to go."
The defeat marked the D-backs' seventh consecutive home loss to the Padres and the second time Arizona has been swept by its National League West division rival at Chase Field since July. Prior to this season, the D-backs had never been swept at home by San Diego in franchise history.
"They played some good defense and we weren't able to get enough runs," D-backs outfielder Chris Young said. "It's been tough, you can't underestimate any team out there. They've been playing some good baseball against us. We haven't been able to pull it out against them."
Aaron Hill blasted a two-run homer in the eighth to pull the D-backs to within one run, but Chris Johnson struck out later in the inning with two runners in scoring position to end the comeback.
Justin Upton added two base hits Sunday to extend his streak of reaching base at home to 19 consecutive games. The outfielder nearly had a third hit immediately after Hill's 20th home run but Padres shortstop Everth Cabrera made a stellar play in the hole to take it away.
"Our guys fought hard, we just weren't able to finish the comeback," Gibson said. "We pressed pretty hard and we came out with good energy, they beat us. They made outstanding plays on us. When you get on these streaks, it doesn't seem fair."
Pitching on normal rest but short notice due to the trade of scheduled starter Joe Saunders on Sunday, D-backs righty Trevor Cahill did little to help his team end its skid.
The 24-year-old turned in his shortest outing in more than a year, tossing just 3 2/3 innings and surrendering four earned runs on eight hits and three walks.
"I wasn't on my normal program but I felt like I should've been able to adjust," Cahill said. "I wasn't able to do that. It's not an excuse, I had plenty of time to prepare, I didn't execute. I didn't throw the ball real well and when I did make good pitches, they found holes."
After throwing a complete game shutout against the Padres on June 3, Cahill has given up a combined eight runs in just 9 2/3 innings over his last two starts against the team.
Moreover, the right-hander continued his season-long first inning woes Sunday, allowing five consecutive batters to reach base with two down, plating two runs.
In 26 first innings this season, Cahill has now surrendered 19 earned runs.
"It was not good, he was unable to locate the ball when he needed to make a pitch," Gibson said. "Trevor just didn't have a good performance. He's very inconsistent with where he wants to throw the ball."
Cahill served up two more two-out RBI hits before leaving with two outs in the fourth inning and forcing his bullpen to work 5 1/3 innings after throwing a combined 8 2/3 innings on Friday and Saturday.
After the D-backs failed to capitalize in the sixth thanks to Montero's double-play ball, the Padres cashed in on the momentum in the seventh when Alexi Amarista drove in San Diego's fifth two-out and eventual game-winning run with a RBI single to extend the lead, 5-2.
"All their runs came with two down," Gibson said. "That makes it tough. You'd like to think you can put them away. That's pretty tough sledding. It's frustrating but we'll play hard tomorrow, we can't do anything more than that."
Tyler Emerick is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.