The Annville-Cleona senior guard needed four points heading into Saturday night's contest versus Pine Grove at Lebanon Valley College for 1,000 in her stellar career.
A scant 46 seconds into the game, Siebecker achieved that marker with her putback of an errant shot under the glass.
It was the highlight of a night that ran out of steam for A-C, with the Little Dutchmen running out of gas in the fourth quarter in a 45-37 loss to Pine Grove in a girls' basketball non-league matchup.
Siebecker had 24 points to lead her club, but that simple rebound putback of Taylor Winters' missed jumper - it caromed directly to her - with 6:14 to go in the first quarter is a moment she won't soon forget.
"I definitely wanted to get it out of the way as soon as I could so I didn't have to worry about it," Siebecker said. "It was nice how it worked out.
"I was really excited. At the start of the season I thought I had a chance to get it. Then it finally came and I thought, 'Wow, it's finally here. It finally happened.'"
A-C (8-8) was on fumes by the time the date at LVC arrived. The Little Dutchmen played their fourth game in five nights and were without the services of point guard Kayla Parks and center Gabby Battle against the Cardinals. Parks has been nursing a sore ankle, and Battle hurt her ankle Friday night against Garden Spot.
It didn't matter for while, as A-C hung with Pine Grove for a half, trailing 21-20.
Pine Grove trailed as late as early in the fourth quarter, 31-29, after Siebecker hit a 3-ponter to give the Dutchmen a 31-29 lead.
But fatigue and foul problems plagued the Dutchmen in the final stanza, and by the end A-C was running with Siebecker and a contingent of freshmen and sophomores on the floor.
"Coming in I was without those two starters, and in the fourth quarter (Saturday) we had one senior with two freshmen and two sophomores on the floor," A-C head coach Jamie Walborn said. "I think not having that experience played into it; just not being in those situations because they are young players.
"But considering the injuries, and without any practice time, I was very pleased with the effort."
During Siebecker's charge to the milestone out of the gate, the Dutchmen raced to a 6-0 lead. Upon resumption following a brief ceremony honoring the career milestone, however, the Cardinals scored the next nine points to take a 9-6 lead. The game settled onto a see-saw, where it remained for the better part of next three quarters.
Pine Grove's Becky Evans was the best player on the floor Saturday night. Evans willed her club back into the contest early with a personal nine-point run and was the only Cardinal - other than one made free throw from Faith Shaffer - to score for the remainder of the first half.
Evans finished with a game-high 26 points. It was her 3 that pulled Pine Grove back even at 28 with under a minute to go in the third quarter to calm an impressive rally from A-C spearheaded by Siebecker. She also canned three of four from the free throw line with less than a minute to play to quell any attempts at a last-ditch rally by the hosts.
The Cardinals scored 16 of the game's final 23 points to pull away, highlighted by a 13-1 run in the game's final four minutes and change.