Mississippi State (8-5) scored a season-high points total while limiting Troy (3-9) to its second-lowest output of the season.
After a sluggish start on Friday, the Bulldogs made a statement in the opening half and claimed a 48-27 halftime lead they would not relinquish.
"I think you have to be happy with the way we played tonight. It was certainly the best first 20 minutes we've played all year," head coach Vic Schaefer said. "We came out and threw the first punch, the next punch and the next punch. We had some really good execution tonight, and I'm really pleased with the effort from our kids. I think we did well in the press tonight, and we rebounded about as well as we have all year."
Alwal scored 17 of her 21 points in the first half, and Darriel Gaynor added 12 of her career-best 15 points as the Bulldogs shot 48.6 percent from the floor for the opening stanza.
"I've been in a shooting slump, so I had to make sure I wasn't tense when shooting and focus on my follow-through. That helped me get into a shooting rhythm tonight," Gaynor said of her 15-point night.
With the game knotted at four three minutes in, State claimed a lead that it would not relinquish as it out-scored the Trojans 20-6 over the following seven minutes.
An Alwal bucket sparked the streak that included three of Gaynor's four 3-pointers in the half. Jerica James capped it with a pair of free throws to put MSU in front by 14 at 24-10.
Alwal converted an old-fashioned 3-point play to put MSU up 30-13 with 8:01 left, and she added a layup with 6:49 remaining to give the Bulldogs a 21-point advantage.
"I tried to incorporate the mistakes from yesterday's game into tonight's game," Alwal said. "Having back-to-back games was tough, but I tried to push through the fatigue."
After a Kourtney Coleman 3-pointer put Troy within 15 with 5:02 left, State used a 9-0 run to extend the lead to as much as 24 before taking a 21-point advantage to the locker room.
Williams sparked the Bulldogs over the final 20 minutes, scoring 14 of her 20 points in the second half.
"(Carnecia) has put back-to-back games together. We haven't had a kid stack two games all year. You have to take your hat off to that kid," Schaefer said of Williams' performance. "She keeps getting dinged up on her knee and bounces back with a lot of toughness. She's a great help defender and probably in the best shape of her life right now."
The Memphis native opened the half with six-straight points as the Bulldogs extended the halftime advantage to 54-27.
The Trojans gained some momentum and cut the Dawgs' lead to 16 with 11:17 to play, but Williams regained the edge for State, scoring eight-unanswered points to push the lead to 68-44 with 8:13 to go.
Troy would get no closer than 21 the rest of the way as Mississippi State won its seventh-straight game at Humphrey Coliseum.
Alwal and Williams both recorded double-doubles, adding 12 and 10 rebounds, respectively. It was the second-straight double-double and sixth of the season for Alwal as she scored 10 points and grabbed 13 rebounds in Friday night's 65-49 win against Northwestern State.
In the weekend's back-to-back games, Williams combined for 36 points and 18 rebounds after she tallied 16 points and eight boards on Friday.
Against Troy, the Bulldogs hit 31-of-69 shots for 44.9 percent. State was 5-of-15 (33.3 percent) from 3-point range while knocking down 75 percent of its free-throw attempts (15-of-20).
State limited the Trojans to 37.9 percent from the floor, including a 21.4-percent tally from 3-point range, and claimed a 48-35 advantage on the boards.
Mississippi State forced 25 turnovers, its third-most of the season, while committing 18. The Bulldogs dished out a season second-highest 18 assists.
Kendra Grant finished the night with nine points for Mississippi State. Jessy Ward tied her season high with six, while Katia May and Sherise Williams added four points each.
Sarah McAppion was the lone Troy player in double figures with 23.
The Bulldogs hit the road to open the SEC slate, venturing to Vanderbilt on Jan. 3 for a 7 p.m. tip. Following the league-opening trek to Nashville, State hosts South Carolina Jan. 6 and Florida Jan. 10.