PHOENIX -- When you look at Caleb Smith's line score from Sunday night's game, it's easy to conclude that he did not pitch well.

But if you scratch a little deeper under the surface of Arizona's 5-2 loss to the Giants, you could understand how the outcome could have been different.

"You know he was one pitch away or one at-bat away from making his line score look totally different," D-backs manager Torey Lovullo said.

In four different plate appearances, Smith was one strike away from retiring a hitter only to watch him reach base.

In the first inning, Smith had two strikes on Austin Slater and Buster Posey, but both were able to then hit bloop singles that helped lead to a two-run first inning.

The one hard-hit ball in the inning came when Darin Ruf laced a double to left-center that scored Posey.

"I thought I pitched better than what the scoreboard showed," Smith said. "Things went their way in the first inning with two broken-bat hits that barely got over our infielders' heads, then I made a mistake to Ruf. It was just a fastball middle-middle. He hit a double."

Then in the sixth, Smith retired the first two batters of the inning and got two strikes on Posey before walking him.

That would prove to be costly because after Smith jumped ahead 1-2 on the next batter, Ruf, he hung a curveball and Ruf made him pay by hitting a homer into the left-field bleachers that made the score 5-0.

"That [sixth] inning, it hurt," Lovullo said. "It drove the score to 5-0. It changed the whole dynamic of what remained of this game."

Smith tipped his cap to the way the Giants hitters made him work throughout the game.

"They had some good at-bats and they made me work for every out," Smith said. "They’re a good hitting ballclub.”

While there were fireworks postgame in honor of the Fourth of July, the D-backs offense did not show much firepower against Anthony DeSclafani. They did not get their first hit until the fifth and finally got on the board in the seventh when Josh Reddick singled home Asdrúbal Cabrera.

"It looked like he had more than just one pitch going," Lovullo said of DeSclafani. "It was an aggressive fastball. [He threw] down fastballs to both sides of the plate and he threw a number of breaking balls and offspeed pitches behind in counts. When you’re trying to lean on a fastball and then he changes speeds, it becomes a little more of a challenge."

With the loss, the D-backs dropped three of four to the Giants and are still searching for their first series win since taking three of four from the Rockies on April 29-May 2.

"I think we continue to fight," Lovullo said. "We're staying in games. We brought up the tying run to home plate in the ninth after being down 5-0. And it just continues to be the trend that we see late in these games that these guys are still fighting. We got to close up some gaps. We got to figure out a way to win some baseball games. We're a good baseball team. We're a much better baseball team than our record."