Amanda Nunes won in spectacular fashion. Jon Jones barely hung on.
Both champions still emerged from UFC 239 with their belts around their waists.
Nunes stopped Holly Holm late in the first round to defend her bantamweight title, and Jones squeaked out a split-decision victory over Thiago Santos to defend his light heavyweight title on Saturday night.
A two-division champion on a nine-fight winning streak, Nunes (18-4) remained the pound-for-pound ruler of her sport with her usual devastating flair. After she floored Holm (12-5) with a perfectly timed kick to the head, she mercilessly finished Holm with punches on the ground with 50 seconds left in the first round.
"I told my coaches I wanted to knock her out the same way she knocks people out," Nunes said of her opponent, an accomplished kickboxer. "I did it tonight. She was the only former champion I didn't beat yet. Now I beat her, and I'm very happy."
Jones (25-1) had much more trouble with Santos (21-7), who nearly scrapped his way to victory despite injuring his left knee early in the fight. Jones fought cautiously and earned a 48-47 decision on two of the three judges' scorecards.
"He implemented a game plan I think a lot of people have wanted to for a very long time," Jones said. "He did a good job. He exploited a hole in my game that won't be there next time."
Until Jones' tactical victory, UFC 239 was all about violence.