Vasquez, who scored 15 points in the first half, was 8 of 9 from the field and had 12 assists in his 19th double-double of the season.
Ryan Anderson added 14 points and Robin Lopez 11 for the Hornets, who were making a rare appearance in New Orleans Arena. Because of the Super Bowl this past week, the Hornets were playing only their second home game in the past eight and fourth in the past 13.
"One of the primary focuses of the two practices on Monday and Tuesday was just our aggressiveness," Lopez said. "We want to make sure we went out there and beat up on each other, and it was nice to see some carry-over."
The Suns' perimeter-based offense struggled, as Phoenix as 35 of 78 from the field and 1 of 15 on 3-point attempts.
"Tough, tough loss for us," said Suns interim coach Lindsey Hunter, who is 4-5 after taking over for Alvin Gentry on Jan. 20. "Not many positives can be taken from the game tonight. Like I said, I am discouraged but I am still encouraged because I know where we are going to be and I know how we are going to do it."
The Hornets trailed 61-60 with 7:09 left in the third quarter, but with Lopez scoring four points on offensive rebounds off a pair of misses by Eric Gordon, the Hornets went on a 13-2 run to take a 73-63 lead. Lopez finished the quarter with seven points and Vasquez had five assists.
"I don't think I played different than any other game," said Vasquez, who had 12 assists and no turnovers for the first time in his career.
"Tonight was just one of those games that was perfect for me," he added. "If Kobe (Bryant) does it or (Steve) Nash or Chris Paul, they're the best. Me doing it, I'm nobody yet."
Phoenix trailed 78-71 after three quarters but cut the Hornets' lead to two midway through the fourth. Anderson's 3-pointer and a layup by Lopez quickly built the lead back to seven.
As he had in the second quarter, Williams sat his starters for the early part of the fourth quarter.
"When you have two rookies in the backcourt and a 21-year-old as a small forward, you don't have a lot of experience," Williams said. "I like the fact they weren't afraid and the same time we were getting stops, so it didn't hurt as bad, We were able to get our starters back in there and close it out."
Williams kept his starters on the bench for nearly half of the second quarter, but Phoenix was unable to build any separation against the Hornets reserves. The Suns' 27-26 first-quarter lead turned into a 37-35 deficit at the 7:31 mark of the second quarter when Gordon, Vasquez and Davis returned to the lineup.
New Orleans' bench outscored the Suns' bench 20-15 in the first half, but a 24-14 edge in rebounding kept Phoenix close.
The Suns scored 11 second-chance points and held New Orleans to zero. Scola and Dragic each scored 11 points in the first half.
Gordon was 3 of 14 from the field and finished with nine points.
"I am still not 100 percent," said Gordon, who sat out much of the early season with a knee injury. "I am battling through it."
NOTES -- Aminu has record double-digit rebounds in 14 games this season. ... The Hornets are back on the road Friday, playing at Atlanta. ... New Orleans committed 13 turnovers after averaging 16.4 in the previous five games.