LOS ANGELES -- Catching a home run ball at a baseball game is supposed to be a once-in-a-lifetime experience -- if you're lucky. For Keith Hupp, a 54-year-old retired police officer and lifelong Los Angeles Dodgers fan, it has almost become routine.

Hupp caught Justin Turner's walk-off home run Sunday night as the Dodgers defeated the Chicago Cubs 4-1 to take a 2-0 lead in the National League Championship Series. The home run came 29 years to the day (and just 40 minutes short of being to the exact minute) of Kirk Gibson's famous walk-off home run in Game 1 of the 1988 World Series. The whereabouts of that ball are still a mystery to this day, but it was clear Hupp was the one who caught Turner's home run as he was alone as he leaned over the side of the covered seats in the left-field pavilion and nabbed the ball with his glove.

When he was shown on television and on the scoreboard raising the ball above his head, several Dodgers staff members knew exactly who had caught it.

Just last month, Hupp, who has caught 10 home run balls this season and 18 over the past two, gave Dodgers rookie first baseman Cody Bellinger his record-tying (35) and record-breaking (36) home runs balls when he surpassed Mike Piazza for the Dodgers rookie home run record.

35 & 36!



Dodger fan Keith Hupp left San Diego with the historic baseballs and today he delivered them to @Cody_Bellinger and his parents. pic.twitter.com/C9OorLvHLK — Los Angeles Dodgers (@Dodgers) September 9, 2017

"The Dodgers arranged for me to meet Cody along with his mom and his dad," Hupp said. "I gave him home run balls 35 and 36 and Cody did the coolest thing for me. He gave me two game balls in return. One said, 'Keith, thanks for returning home run ball #35,' and the other one said, 'Keith, thanks for returning home run ball #36' and he signed them both.

"For me, that's better than having the real thing. He also gave me a jersey and a bat. It was just nice to meet him and his parents as a Dodgers fan."

Hupp, who was a police officer for 33 years, retired from the South Gate Police Department a little more than two years ago as a captain. He has been a season-ticket holder for more than 20 years and has been in the left-field pavilion for the past 10 seasons as the Dodgers have won seven NL West titles and gone to the NLCS five times. The San Gabriel native attended Sunday's game with his 29-year-old son, Lindley.

Turner called Sunday's home run -- which was just the second postseason walk-off home run in Dodgers history -- the biggest home run of his life. It could be argued the second biggest was Turner's home run in Game 3 of last year's NLCS at Dodger Stadium to help the Dodgers take a 2-1 lead over the Cubs. Well, Hupp caught that ball too. Turner didn't request the ball that night as the Dodgers won 6-0 before losing the series in six games but he did sign it later for Hupp at the team's annual FanFest before the start of spring training.

Sunday, however, was different

"When JT came up to bat I turned to my son and said, 'Hey, it was almost one year ago today that he hit that home run, wouldn't it be cool if he hit one and I caught it again?'" Hupp said. "During his first three at-bats I was envisioning the flight of the ball and he didn't hit a home run.

"And in the ninth inning, he hit it, and it looked like it was tailing and going into center field and man, did I get lucky. I ran across as quick as I could and I reached out three or four feet and caught it."

After the game, the Dodgers brought Hupp and his son back to meet Turner. Hupp gave the ball to Turner and he and his son took photos with Turner and Dodgers closer Kenley Jansen. While there was no official exchange on Sunday, Hupp expects it will be similar to what he got in return from Bellinger.

"I didn't ask for anything, but they told me they would hook me up, and I'm sure they will," said Hupp, who had 213 text messages on his cell phone by the time he got home before midnight. "That was the biggest ball I've ever caught. I thought the biggest ball I'd catch in my life was earlier this year when I caught the game-winning home run ball from Ian Kinsler when the USA won the World Baseball Classic at Dodger Stadium."

Hupp said he is donating that ball to the Baseball Hall of Fame in Cooperstown. While he has a vast baseball memorabilia collection at home, he said doesn't collect home run balls for money.

"I retired a couple of years ago, and I said I was going to spend my retirement income on baseball," Hupp said. "Last year I went to 109 games, and this year I went to 127 games. I went to all the games at Dodger Stadium this season and 46 games on the road. I've gone to all the playoff games. I always sit in the outfield because I try to catch home run balls.

"I'm an old guy, I'm 54 years, and when I see the ball coming at me, it's such a rush. I got mobbed after I caught the ball [Sunday]. There is nothing like it."

Keith Hupp meets Dodgers closer Kenley Jansen and Justin Turner, who holds his NLCS Game 2 walk-off home run ball, which Hupp caught in left-center field. Courtesy of Keith Hupp

Of course, it's no accident that Hupp has caught 18 home run balls over the past two seasons. Not only has he sat in the outfield for 236 games during that time, but he reviews the tendencies of each batter coming to the plate that night and tries to be as close to where the percentages say a home run ball from that batter will drop. Sometimes he catches it on the fly near his seat and other times he has to run down the stairs below his section to nab it as he did with Chris Taylor's first grand slam at Dodger Stadium earlier this season.

"I study the ESPN Home Run Tracker before every game," Hupp said. "I'll try to position myself to be in the best spot based on the player and pitcher. I track the home runs of every player in MLB, so I have an idea of where a home run ball might go.

"When I go to a game, there's just something in me where I want to catch the ball, so I always sit in the outfield and I always have an aisle seat."

Bellinger's record-tying and record-breaking home run balls that Hupp eventually gave to the Dodgers rookie weren't actually caught by Hupp and aren't included in his total of 18 over the past two seasons. Hupp came close to catching both balls, but when he couldn't catch them himself he quickly offered to buy the balls from the fans who did catch them.

"I almost caught the first one, I missed it by six feet, and the second one I ran up the stairs and the ball sailed over my glove by three feet," Hupp said. "I bought both of them immediately with the idea of returning them to Cody. Those are the only two balls I've ever bought in my life because I knew they were historic. I bought the first one for $300 and the second one for $500. I got offered a huge amount of money from collectors, but when a player wants a ball back, I'd rather give them the ball."

Hupp will be traveling to Chicago for the NLCS on Monday and plans to go to the World Series if the Dodgers advance there for the first time since 1988. As much success as Hupp has had catching home run balls over the past two seasons, he admits there is one thing he still needs to do.

"I'm not done yet," Hupp said. "I've been waiting for the Dodgers to get back to the World Series for 29 years. I have to catch a World Series home run ball -- a Dodgers one, of course."