CHICAGO – Cubs reliever Nate Pearson stood on the mound, jaw dropped, hands atop his head in disbelief. Ian Happ sat in the dirt in foul territory up the left-field line, shifted to a knee and tossed in the baseball that he had no business catching on Saturday afternoon.

In the seventh inning of the Cubs’ 7-1 win over the Padres, Happ celebrated his 1,000th career game with the franchise by showing fans one of the reasons he developed into a key cog in the current core. He chased down a tailing fly ball off the bat of pinch-hitter Gavin Sheets, snaring it with a spectacular diving catch.

“That was an awesome play,” Cubs manager Craig Counsell said. “The ball was hit and you’re kind of like, ‘Oh no.’”

The way the wall juts out makes it difficult for those in the Cubs’ dugout to see what happens when an outfielder reaches that part of the field. When the Wrigley Field faithful released a collective gasp, followed by a raucous roar, Counsell knew Happ made the play.

“The crowd helped us out there,” said the manager. “Heck of a catch. Heck of an effort.”

The play in question came with a catch probability of just 25%, per Statcast, but Happ has spent the past several years learning the ins and outs of how to navigate left in Wrigley Field. His mastery of that section of the ballpark -- where the side wall sits only a few feet from the chalk line -- helped him become the only Cubs outfielder to have three career Gold Glove Awards.

Happ has a knack for making plays near that wall, but often will use a feet-first slide to protect himself as he corrals a sinker line drive. In this case, the left fielder dove forward, made the catch and landed hard. His momentum forced him to roll over, hitting the thin padding that covers the bricks.

“There’s not much foul territory,” Cubs shortstop Dansby Swanson said. “Just the way the outfield is shaped is different than most places, and he’s obviously a true pro, right? He gets his work in, he knows where he is on the field at all times. To me, that’s almost more impressive than the actual defense itself.”

It was one more chance for the North Side crowd to stand up and give Happ some well-deserved recognition.

In the first inning, the fans inside the Friendly Confines gave Happ a rousing standing ovation, celebrating his milestone as the 32nd player in team history to reach 1,000 career games. He joined Mark Grace and Shawon Dunston as the only players drafted by the Cubs to notch at least 1,000 games with the franchise.

Happ raised his helmet to the crowd and it was not lost on him that one of his mentors -- former Cubs outfielder Jason Heyward -- was looking on from the Padres’ dugout.

“I was trying not to get emotional out there,” Happ said. “Being able to tip the helmet to the fans and teammates, Jason being in the other dugout, all of those things were really special. It was just a really cool moment.”

Happ -- selected by the Cubs in the first round of the 2015 Draft -- became the 21st player to have his 1,000th MLB game also be his 1,000th game for the team. Anthony Rizzo (2018) and Aramis Ramirez (2011) were the last two players to reach the mark for the Cubs. Happ is one of eight active players to have at least that many games with one team.

“The big significance for me is 1,000 games with the same team,” Counsell said. “That, in this era of baseball, is not happening. It’s just not happening. And that speaks a lot about kind of how Ian’s gone about it, I think. It’s hard to do.”

Happ thanked the crowd for its support by drilling a pitch from San Diego’s Nick Pivetta to deep center field for a leadoff double. He added a walk in the second inning, setting up a bases-loaded free pass by Kyle Tucker that helped get the lineup rolling in support of a stellar six-inning start by lefty Matthew Boyd.

“For me to do it here, have 1,000 games in this uniform,” Happ said, “in this city, all the great guys that have come through -- coaches, people, support staff, everybody that’s helped make it happen -- it means a lot.

“Going out there with the fans, being able to do that, I’m so proud to be a Cub.”