PHOENIX -- As Justin Upton slumped in April, critics suggested that he would be an ideal No. 3 hitter -- at Triple-A Reno.

The 21-year-old outfielder has emerged from his early struggles to become one of the more potent three-hole hitters in the major leagues.

Upton homered, doubled and drove in three runs, and Max Scherzer won his third straight start as the Arizona Diamondbacks defeated Texas 8-2 on Tuesday, sending the Rangers to their fifth straight loss.

Upton, who opened the season with one hit in his first 17 at-bats, raised his average to .324. He has 14 home runs, 17 doubles and 45 RBI.

"I'm happy for him," manager A.J. Hinch said. "He's a legitimate three-hole hitter in the major leagues.

"It's a pleasure to watch him," Hinch said. "He's playing with some urgency."

Upton, the top overall pick in the 2005 draft, said he mostly rolled his eyes at April speculation that he needed to go to the minors for more seasoning.

"Obviously, to play at this level, you've got to be confident in your abilities," he said.

Felipe Lopez had three hits and drove in three runs, and Stephen Drew added three singles for the Diamondbacks, who snapped a three-game skid.

Scherzer (5-4) worked out of jams for most of the night, allowing two runs on seven hits and a walk in six innings. He struck out seven.

Staked to a 7-2 lead after four innings, Scherzer kept the Rangers at bay.

"The way we've been having trouble putting runs on the board, falling back that deep, I knew it was going to be a tough road to come back, especially with Scherzer up there," Texas manager Ron Washington said.

The slumping Rangers hit a new low in the sixth, handing the Diamondbacks a gift run on a play straight out of Little League.

With two out and Lopez on third, Rangers catcher Jarrod Saltalamacchia fired his throw over 6-foot-2 pitcher Jason Jennings' head. Jennings hustled after the ball, but Lopez dashed home without a play as the Chase Field crowd roared with delight.

Saltalamacchia was charged with an error on the play, which gave Arizona an 8-2 lead.

After the run scored, Saltalamacchia turned and spoke to plate ump Mike Everitt. Saltalamacchia later said he thought time had been called when a new ball was put into play.

"I thought he had already called time, so that's what the argument was about," Saltalamacchia said. "But it was a terrible throw. I've got to get the ball back to the pitcher, simple as that."

The Diamondbacks jumped out to a quick 2-0 lead in the first against Matt Harrison (4-5). With one out, Drew singled and scored on Upton's homer to right field, which apparently deflected off right fielder Nelson Cruz' glove.

Upton chuckled when asked if Cruz might have helped the ball over the fence.

"It was already over," Upton said. "But he got a piece of it. He made a great play."

Arizona made it 4-0 in the second on Lopez's two-run single.

The Rangers whittled the lead on Marlon Byrd's RBI double in the third and Ian Kinsler's run-scoring single in the fourth. But the Diamondbacks responded with a three-run burst in the fourth, capped by Upton's RBI double.

Harrison lasted 3 2/3 innings, his briefest outing.

In four starts from April 27-May 14, Harrison went 4-0 and allowed six earned runs in 30 innings. In the four starts since -- a span that includes a stint on the DL with an inflamed left shoulder -- he's 0-3 and has given up 22 runs in 18 2/3 innings.

Notes

• Rangers OF Josh Hamilton, who is returning from abdominal surgery, is doing some baseball activities but has yet to face live pitching.
• Arizona CF Chris Young was a late scratch with a groin strain. Gerardo Parra took Young's spot in the lineup.
• Texas made its first regular-season trip to the desert since July 2000. The Rangers have trained in suburban Surprise since 2003.