He swung like a new man, too.
Asked if his new look made him hit better, Clark chuckled and said, "If it was, I'd have cut it a long time ago."
Clark, who came into the game hitting .140, tied the score 5-5 with a solo homer off reliever Scott Linebrink in the eighth inning.
Arizona handed the NL West leaders their second defeat in 16 games and snapped the Padres' franchise-record eight-game road win streak.
"They're playing better than anybody else in baseball, and to get that first game of the series, especially with their ace (Jake Peavy) going (Tuesday), that was big for us," Green said.
The Padres were stunned by the loss, which reduced their lead over Arizona to a half-game in the NL West. The Diamondbacks are 4-0 against the Padres after sweeping a three-game series in Petco Park last month.
San Diego manager Bruce Bochy said his team "did a great job of coming back. Fought back and had the lead, and those are tough to lose. We have to put this behind us. They battled tonight and we made a couple of mistakes and it haunted us."
Linebrink's mistake was an inside fastball to a hitter who earned a reputation for late-inning heroics last year. Clark was chosen the Diamondbacks' 2005 Player of the Year after hitting .304 with 30 homers and 87 runs batted in in only 130 games.
This year has been very different for the 33-year-old Clark, who had one homer in his first 53 at-bats.
"Tony's going to do a lot of great things for us," Green said. "Obviously last year, he had an incredible year. I think sometimes after you have a year like that, it's tough to start all over. You put a little extra pressure on yourself to try to replicate the previous season. He's going to have a great year. He got off to a slow start, but nights like tonight are going to get him going."
Clark decided his Afro had to go after he stepped off the Diamondbacks' charter flight from St. Louis Sunday night.
"As soon as I got off that plane and felt that 100 degrees -- I had six or seven inches of insulation," he said.
Clark's homer cost San Diego starter Chan Ho Park his third victory. Park allowed one earned run on five hits in seven innings, walking two and striking out eight.
The shot also set the stage for Arizona's first extra-inning victory of the season.
That brought up Luis Gonzalez, who bounced to shortstop, with Byrnes holding at second. The Padres intentionally walked Clark, a switch-hitter, to get to the left-handed Green.
Green singled past second baseman Josh Barfield.
"When it was 2-0, I was in the driver's seat," Green said of the count.
Jose Valverde (1-1) earned the victory with a scoreless 10th.
Arizona starter Brandon Webb, who came in 6-0, was hit hard after being spotted a 4-0 lead in the third inning.
Arizona has scored at least four runs in all but one of Webb's nine starts.
Three batters later, Adrian Gonzalez homered into the Diamondbacks' bullpen in the left-field corner. After allowing three homers in his first 61 2-3 innings, Webb surrendered two in a span of four batters.
Webb's struggles continued in the sixth. After Bard led off with a single and Khalil Greene doubled, Webb threw a called third strike past Vinny Castilla. An intentional walk to Gonzalez loaded the bases for Barfield, who struck out on a low breaking pitch.
That brought up Park, an .083 hitter who had singled in his first two trips. He bounced another single up the middle, driving in two runs to give the Padres a 5-4 lead.
"If I had got Park out, I'd have been all right," Webb said. "He owned me tonight."
Webb allowed five earned runs and 10 hits in sixth innings, walking one and striking out four.
"Still undefeated," he said. "It was not one of my better outings."
- Park matched his hit total in 10 games with the Padres a year ago.
- Webb has allowed 10 hits in each of his last two starts and three times overall this season.
- The game drew an announced crowd of 19,838, the third smallest this season at Chase Field.