But Post 158 did not want to back into the five-team zone event that begins Thursday at Capaha Field.
Jackson was intent on winning just the program's second district title and first since 2005.
Second-seeded Post 158, the host squad for the four-team district tournament at Legion Field, beat third-seeded Cape 11-5 on Sunday to capture the championship.
"Now we can look forward to the zone."
Jackson (36-15) went through the double-elimination district tournament without a loss, going 3-0. Post 158 also beat Cape 15-4 in Friday's opening round. Post 63 emerged from the losers bracket to reach Sunday's title round.
Cape (17-29) will join Jackson in the zone tournament because it is hosting the event for the third consecutive year. If Post 63 had won the district tournament, then the runner-up would also have qualified.
"We needed to play good regardless, whether we were in the zone or not," Lewis said. "We've been in a lot of [district] finals over the years. It feels good to win one."
Post 158's offense took control after Post 63 starter Alex Davie ran out of gas on the hot day.
"He was good," Lewis said. "I think he wore down a little bit."
Jackson got a strong outing from Joe Elfrink.
"Joe gave us a chance with a good, solid start," Lewis said.
"I was controlling my fastball and working in offspeed," Elfrink said. "I was trying to work ahead. I have a great defense behind me."
Elfrink said he was told after Saturday's winners bracket final victory over top-seeded Dunklin County that he would be getting the nod Sunday.
"I was very excited," he said.
Jackson took control of the game with a four-run seventh inning that featured four doubles and snapped a 2-2 deadlock.
Simmons led off with a double and scored the go-ahead run on a one-out double by Cody Harris.
Lane Thompson's double plated Harris and knocked out Davie. Trent Wills' double off reliever Logan Henson scored Thompson. Wills later came home on an error.
"We were all energized and we were all hitting the ball," Harris said.
Davie allowed eight hits and five runs, four earned, over 6 1/3 innings. He struck out three and walked two.
"He pitched his tail off," Cape coach Steve Williams said. "He just ran out of gas."
Cape scored two unearned runs in the seventh inning to pull within 6-4, but Jackson answered with three runs in the eighth.
Post 63 made it 9-5 in the bottom of the eighth inning before Jackson closed the scoring with two runs in the ninth.
"Jackson is hot right now," Williams said.
Jackson had 14 hits, nine of which came over the final three innings when Post 158 scored nine of its 11 runs.
Eight of the nine batters in Jackson's lineup got hits, and Post 158's bottom two batters produced five hits and five RBIs.
Harris, the eighth-place batter, had three hits and two RBIs. Thompson, batting ninth, had two hits and three RBIs.
"It's nice to have a hot lineup one through nine," Harris said.
Simmons, Cody Heisserer and Laban Petzoldt all added two hits for Jackson. Simmons also walked twice and scored four runs. Ryan O'Rear contributed two RBIs.
"We started getting base-runners and our offense started clicking," Simmons said.
Travis Smith had two of Cape's seven hits.
Alex McRaven homered leading off the fourth inning to break a scoreless tie. Cape added an unearned run in the frame on an RBI single by Andrew Williams.
Jackson drew even with two runs in the fifth inning -- one run was unearned -- before pulling away.
Adam James pitched an inning for Jackson, allowing three runs but just one earned.
Caleb Rowald, who pitched the final four innings without allowing a run Saturday against Dunklin County, finished Sunday's victory with two scoreless innings.
"It was a good tournament for us," Lewis said.
Cape will play its zone tournament opener at 3 p.m. Thursday, while Jackson will play at 6 p.m. There also will be a game at 9 p.m.
The pairings for the double-elimination have not yet been announced, but rounding out the field are Festus, Creve Coeur and Ballwin.
There also will be games at 3 p.m., 6 p.m. and 9 p.m. Friday. The losers bracket final will be at 5 p.m. Saturday, with the championship set for 8 p.m.
An if-necessary title contest would be played at 2 p.m. Sunday.
Festus is the three-time defending state champion. This year's state tournament will be played next week in Sedalia, Mo.