"It was kind of indescribable," the 23-year-old outfielder said after helping the Diamondbacks beat the Los Angeles Dodgers 5-2 on Thursday night. "Everyone was on their feet cheering. It was like, 'Whoa, did I just do that?'"
Quentin, promoted from Triple-A Tucson earlier Thursday, hit a two-run home run off Dodgers starter Mark Hendrickson (0-3) in his third at-bat.
"He hung a curveball and I got it," Quentin said. "I put a good swing on a mistake."
Arizona starter Brandon Webb (11-3) made few mistakes, as usual. He allowed two runs and seven hits and lowered his National League-leading ERA to 2.51. Webb walked two and struck out four.
"Today I had pretty good stuff," said Webb, who won his third decision in a row. "My arm felt great."
Jorge Julio pitched the ninth for 11th save in 12 opportunities.
The victory lifted third-place Arizona within two games of NL West leader San Diego. Arizona has won eight of 10 since being swept by the Dodgers in a three-game series earlier this month.
With every victory, the Diamondbacks bear little resemblance to the team that stumbled to an 8-20 record in June. Arizona is 21-16 (.568) against the NL West, the best winning percentage in the division.
"We've kind of re-established ourselves in the division after a tough stretch," manager Bob Melvin said.
The Dodgers dropped to 1-7 since the All-Star break, all on the road. They open a nine-game homestand against St. Louis on Friday.
"I just see a team that things just aren't happening for them right now," Los Angeles manager Grady Little said. "The effort is there. It's something we've got to get through."
Hendrickson lasted 5 1/3 innings, allowing five runs and nine hits.
While pitching for Tampa Bay, Hendrickson beat the Diamondbacks on June 20 in St. Petersburg. The Diamondbacks wasted no time getting to him in the rematch.
Eric Byrnes led off the first with a single, stole second and scored on Conor Jackson's single to put Arizona ahead 1-0.
The Dodgers tied it on Ramon Martinez' double play grounder in the second. But the Diamondbacks went up 3-1 in the bottom of the inning on doubles by Chad Tracy and Stephen Drew and a single by Orlando Hudson.
The Diamondbacks added two runs in the sixth on Quentin's 390-foot homer to left field.
"One of those games that's kind of frustrating because I felt like I had pretty good stuff," Hendrickson said.
Hendrickson needed to pitch much better to match Webb, who has been in a groove since he went 0-3 in four starts from June 10-27. In the last start of that sequence, Webb gave up a season-high seven runs in seven innings against Seattle.
In four starts since then, Webb has allowed only four runs in 31 innings.
He dominated a Dodgers team whose .280 batting average leads the league. His fielders helped by turning four double plays, tying a club record.
In the seventh, Webb gave up a leadoff double to Andre Ethier and walked Willy Aybar. He escaped the jam by getting Jose Cruz Jr. to bounce back to the mound, starting a 1-6-3 double play. Webb's 104th and final pitch also produced a double play grounder, by Nomar Garciaparra to end the eighth.
"He's not the guy we wanted to see today," Little said. "He was on the top of his game. A couple of times there we thought we had a chance, and then here comes that double play ball and that was the story."
But Quentin was the real story. The former Stanford star and the Diamondbacks' first-round draft pick in 2003, is considered a big part of Arizona's future.
Quentin thought he'd never see the home run ball again, but the fan who caught it returned it and didn't ask for anything in return.
"The guy gave it back," Quentin said. "He didn't want anything. He wrote me a note. I think I'm going to send him maybe a bat or something, and say thank you."
- Quentin is the third Diamondback to homer in his major league debut joining Travis Lee and Alex Cabrera.
- After starting his big league career 0-for-8, Stephen Drew is 7-for-15. His second-inning double was his fourth consecutive extra-base hit. Drew had two doubles and a triple in his final three at-bats Wednesday night.
- Drew's double came in the same inning his older brother, J.D., doubled. J.D. Drew is 6-for-12 lifetime against Webb.
- The game drew 25,294. The Diamondbacks are averaging 24,194 per game, which puts them on a pace to draw 1,959,761. They drew more than 2 million in each of their first eight seasons but have seen attendance decline six of the last seven years.
- Arizona OF Byrnes has not struck out in 56 consecutive plate appearances, the longest streak in the majors.