Cameron Barnes and Jim Walter each hit 3-pointers for Hardin-Simmons in the first 75 seconds against No. 18 Baylor.
That early lead by the Cowboys was short-lived against the bigger Bears.
Brady Heslip and Rico Gathers each had 17 points to lead six Baylor players scoring in double figures, and the Bears won 104-59 on Sunday in their only game between their first loss in Hawaii and playing another top 10 opponent.
"I think that Scott (Drew) has assembled a team now that is just one echelon away from being one of our premier teams in the country. He's already consistent with their tournament play in the Big 12. In Maui, you saw with Syracuse, they're just right there," Hardin-Simmons coach Craig Carse said. "Naturally, as an NCAA Division III non-scholarship team, we don't have the length, the height, the vertical, the talent. They have a wonderful team."
Hardin-Simmons (0-4) has lost its last 11 games against Baylor — the last six by an average margin of more than 51 points — since the Cowboys last won in the in-state rivalry during the 1936-37 season when they had a 12-7 series lead.
Baylor played three games in three days earlier in the week at the Maui Invitational, leaving Hawaii with its first loss after a 74-67 loss to No. 8 Syracuse in the tournament's championship game Wednesday night. This was its only game between then and playing No. 3 Kentucky in the Dallas Cowboys' stadium Friday night.
"It was the first game back and it's good to get this one out of the way," Baylor coach Scott Drew said. "That first game back you're never 100 percent. We were gasping for some air at the beginning of the game. It takes a couple of days. ... One of the toughest things coming back from Hawaii, it takes a couple of days, and playing a game gets it out of your system quicker."
Jefferson had 16 points and 10 rebounds for his fourth double-double this season, and Heslip had five 3-pointers. Gathers also had nine rebounds.
Barnes had 15 points to lead Hardin Simmons, including one of the Cowboys' two 3-pointers early. They then missed 15 in a row from beyond the arc until Eric Taylor made another with 14:46 left in the game, when the Cowboys still trailed 65-34.
John Barnes added 12 points for Hardin-Simmons, which played for the second day in a row. The Cowboys lost 80-57 to Texas-Dallas on Saturday.
Derrick Jefferson, their leading scorer and rebounder through the first three games, had seven points and three rebounds. Those were well below his averages of 18.3 points and 9.3 rebounds.
Hardin-Simmons had its last lead with 16:22 left in the first half when Taylor made a jumper to make it 8-6. Jefferson then had a tying jumper before Ish Wainright made a layup that put Baylor ahead to stay. That was part of a 15-2 run in a span of just more than 3 minutes when Heslip had two 3s, including one with 13 minutes left that made it 21-10.
Baylor shot 61 percent (20 of 33) from the field while building a 52-27 halftime lead. Jefferson had nine points and seven rebounds by that point.
The Bears then opened the second half with a 9-0 lead that included back-to-back 3s by Heslip. They built as much as a 47-point lead.
"Coming back from Hawaii, you're always sluggish," Carse said. "I've seen every game Baylor has played this year, so today was the most sluggish that they've played. A little flatter. So we're fortunate to play them on a day like this. But this was important to get them back oxygen-wise and get ready for a big game with Kentucky this week, which is a national mark for them. I think they're wonderful."