Clark, who signed a one-year deal with the Padres in the offseason in a move the team hoped at the time would give them some thump off the bench late in games, has either driven in a run or set up a run with each of his three hits.
On Opening Day, Clark gave the Padres a four-run cushion in a 4-0 victory against the Astros with a seventh-inning single that scored Khalil Greene.
On April 8 against the Giants, Clark's pinch-hit single sent Josh Bard to third base. Bard would score one batter later on a sacrifice fly, though the Padres lost, 3-2, in 11 innings.
In the Padres' 7-5 victory over the Dodgers on Friday, Clark's one-out single in the eighth inning ignited a two-run inning.
Clark, primarily an everyday player during his Major League career, said that getting used to pinch-hitting isn't easy, not if you're a rookie or someone who has been in the Major Leagues since 1995 like he has.
"It's a whole different mind-set as opposed to having four at-bats," Clark said. "It's a mental grind, a little different preparation. When you're young and used to playing every day, it's a difficult adjustment to make. But even when you're older, it's a difficult adjustment.
"There's plenty of video, plenty of physical work you can do, running and lifting, hitting in the cage, all in hopes of being sharp in the box that night. You take notes on the history you might have [against a pitcher] and you watch how the game is being called."
Not that any of Clark's early success has surprised manager Bud Black, who expected this kind of production when the team signed the veteran in February right before the start of Spring Training.
"When we looked at Tony, we looked at an experienced guy who understood what it took to be a valuable bench player," Black said. "He's been great as far as being prepared to hit, taking on a strong leadership role on the team already. He's proved to be valuable, and the most important thing is he's played well. His performance has been great."
And Clark is doing it all in San Diego, where he played and starred at Valhalla High and Christian High in nearby El Cajon.
"I've said it since Day 1, it's still hard for me to believe that I'm in the uniform of the team I grew up watching, having the opportunity to have my career come full circle, back in San Diego; it's an absolute blast," Clark said.