Lander improved to 41-6 overall and 22-6 in the conference, moving one game ahead of Columbus State which lost 7-6 to North Georgia Friday.
Armstrong fell to 25-16, 15-13.
The teams will play a double-header Saturday, starting at 2 o'clock to close out the regular season.
Connor Lewis had two singles to break the school record for total bases in a season with 134, edging Jesse Barbaro's total of 133 set in 2007.
Grady smacked his 23rd double of the season, surpassing Barbaro's total of 22 also set in 2007.
Also, Lander's Thomas Berry walked for the 47th time, tying Robert Skinner's school record from 2011.
Armstrong took a 1-0 lead in the top of the fourth when Cody Sherlin singled, moved to second on Tyler Avera's sacrifice bunt, stopped at third on Clayton Miller's ground out, and scored on a single by R.J. Dennard.
Lander took the lead with three runs in the bottom of the fifth. Thomas Bess started the rally by beating out a slow roller to shortstop, stopped at second when Erik Lunde walked, and scored on Patrick Grady's single to right. Lewis's RBI single up the middle gave the Bearcats the lead, and Thomas Berry laid down a suicide squeeze bunt single to score Grady with the third run of the inning. Mitchell Dolan relieved Pirates starting pitcher Ryan Good with the bases loaded and one out, and retired the next two batters to escape what could have been a much bigger inning.
The Pirates had a big threat in the top of the eighth and pulled within 3-2. Dalton Johnson reached on an infield single and moved to second on Sherlin's single to right center. Kyle Tate relieved Wolchik with two on and two out, allowing Miller's RBI single. White relieved Tate and faced Armstrong's top hitter Dennard, and struck him out looking with a pitch on the outside corner.
White retired the side order in the ninth to close out Lander's 41st victory of the season.
Wolchik allowed two runs on five hits in 7.2 innings, striking out seven and walking two.