With point guard and NBA assists leader Steve Nash back from injury and directing traffic, the Suns received 20-plus points from four different players to put up a season-high game total of 133.
The Suns inflicted much of the damage from beyond the arc, hitting 16 three-pointers, including seven by Richardson.
Coach Herb Williams, who replaced Lenny Wilkens after he stepped down Saturday, has been unable to pull the Knicks out of their tailspin and they suffered their seventh straight defeat Tuesday.
Jamal Crawford had a game-high 40 points and Kurt Thomas contributed 24 points and 14 rebounds but it was not enough to prevent host New York losing for the 11th time in 12 games.
In Los Angeles, Vladimir Radmanovic drained 26 points and Ray Allen added 25 as the Seattle SuperSonics eased to a 104-93 triumph over the Lakers.
With leading scorer Kobe Bryant sidelined due to a sprained ankle, the Lakers could not put away the SuperSonics, who won for the first time in six trips to the Staples Center.
Lamar Odom and Luke Walton paced the Lakers with 19 points apiece while Chucky Atkins and Jumaine Jones each added 13.
In Memphis, the surging Grizzlies received double-figure efforts from seven players, led by 18 from Stromile Swift, on the way to a 95-83 victory over the Orlando Magic and their 12th win in 14
Memphis clinched its 12th win in 14 outings despite leading scorer Pau Gasol being out with a foot injury and Bonzi Wells going down with a groin strain.
In Chicago, Kirk Hinrich nailed 23 points and Eddy Curry added 16, including 14 in the final quarter, as the Bulls held on to beat the Denver Nuggets 111-107 for their 11th victory in 12 games.
Carmelo Anthony had 32 points as Denver became the first team in 26 outings to score more than 100 points against the Bulls, who extended their winning streak to four games.
In Charlotte, Paul Pierce scored 33 points, including 14 in the final quarter, as the Boston Celtics snapped a nine-game road losing streak with a 97-92 triumph over the expansion Bobcats.
Pierce did most of the damage from the free-throw line, hitting on 13-of-16 attempts. He also added nine rebounds to help send the Bobcats to a franchise record ninth consecutive loss.
Charlotte's Emeka Okafor was held scoreless in the opening half but broke loose in the second to finish with 20 points, 12 rebounds and five blocked shots.
In Sacramento, Brad Miller claimed a season-high 31 points as the Kings rebounded from their worst home loss in 10 years to pound the New Jersey Nets 113-93.
Two days after being embarrassed by the San Antonio Spurs 103-73, the Kings took it out on the Nets with Peja Stojakovic scoring 25 points and Cuttino Mobley notching 20 points, 10 assists and seven rebounds.