With the series sweep -- and its ninth consecutive victory -- Lander continues its best season ever and improves to 27-3 overall and 15-3 in the PBC. Montevallo drops to 17-13, 8-10. Lander belted 12 home runs in the series.
Lewis broke the record of 11 homers in a season set by Lucas Erwin in 2001 and duplicated by Jordan Owens in 2010.
The Bearcats' Mason McCullough (4-0) earned the victory, striking out five, walking four and allowing two earned runs on two hits.
Montevallo's Alex Pindick (3-3) suffered the loss with one strikeout, three walks and five earned runs on five hits in 3.1 innings.
Lander took a 2-0 first-inning lead when Erik Lunde scored on Thomas Berry's sacrifice fly and Graham Ramos drove in Patrick Grady.
The Bearcats made it 3-0 in the second after Lunde's RBI single plated Chris Hyatt.
Montevallo trimmed the Lander lead to 3-2 in the third on Vinny Rodriguez's two-run homer.
Lander added four more runs in the fourth to make it 7-2 on Lewis' three-run homer and Ramos' RBI single that scored Lawing.
The Bearcats stretched the score to 9-2 in the fifth when Bess and Lewis each had RBI doubles that drove home Chris Hyatt and Lawing.
Lawing homered in the sixth, while Colby Painter and Ramos scored on Thomas Bess' RBI single to make it 12-2.
After Lander added two more runs in the seventh on RBI singles by Painter and Hyatt, then the Falcons cut the lead to 14-5 in the bottom of the inning on a two-RBI double by Jackson Slaid and an RBI single by Thomas Bradey.
Montevallo added three more runs in the eighth when Dane Hutcheon scored on a bases-loaded walk and Slaid drove in Will Fulmer and Chase Bryant with an RBI single to left field.
Lawing's second homer of the game gave Lander its final run in the ninth.
For Lander, Lunde and Lawing had three hits each, while Grady, Lewis, Ramos, Painter and Bess had two.
Fulmer led Montevallo with three hits and Slaid added two.