Williams' teammates and Cleveland's owner Dan Gilbert were dismayed last week when Williams was twice left off the Eastern Conference roster but approved the move unanimously Tuesday.
"It has a beautiful ring to it," Williams said before playing at Indiana. "I'm excited for myself and my teammates and the coaches. It's a great thing, it's one thing people can't take away from you."
Williams wasn't voted in by the fans, nor was he chosen by Eastern Conference head coaches as a reserve. Then he was passed over by Stern in favor of Boston's Ray Allen, who is replacing injured Orlando guard Jameer Nelson on the roster.
The Cavs then took their complaints public, contending they were only team in the top five without more than one All-Star. LeBron James called it a "total smack in the face."
Gilbert was incredulous and poked fun at Williams' snub by using made-up words like 'stupidiculous,' 'idillogical' and 'preposterageous' to describe his feelings.
By Tuesday's pregame interviews, the tone changed.
"I called Mo as soon as I found out. I'm surprised he didn't call and tell me, though," James said, drawing laughter in the locker room. "It's great. It's something we all wanted."
Gilbert was equally pleased.
"It's unfortunate that Chris Bosh is unable to play in this year's All-Star Game in Phoenix," he said in an e-mail to The Associated Press. "The entire Cleveland Cavaliers organization are thankful that the NBA called on Mo Williams to take his rightful place on the Eastern Conference squad. In fact, we think it is 'fantacular,' 'extraordulous' and 'phenomerful.'"
Bosh is averaging 22.7 points and 9.5 rebounds for the Raptors. But he has missed the last three games with the knee injury, including Tuesday night at Minnesota.
"It was mostly our trainers and doctors and Chris himself making the decision," Raptors coach Jay Triano said before the game against the Timberwolves. "I think it's a real sign of Chris not being selfish at all; not trying to play in a game when he's not 100 percent. Now he gets an extra week of rest so he can come back after the All-Star Game and make a run."
The news came after the Cavs morning shootaround and took some, including Williams, by surprise.
Coach Mike Brown said he knocked on Williams' hotel door, and when Williams didn't answer, Brown figured Williams was asleep. So he called Williams' room.
Williams didn't know what was going on, but Brown could hardly wait to inform Williams.
"This is terrific news," Brown said. "Mo has definitely been one of my highlights in my time here."
After two snubs last week, Williams seemed resigned to taking part in the All-Star festivities, but not pulling on an All-Star uniform.
But when Bosh backed out because of a sprained right knee, Williams got another chance.
Heading into Tuesday's game, Williams was averaging 17.1 points, and has provided a needed compliment to James' prowess as the league's second-leading scorer (28.2 points).
Williams has also rejuvenated a team that made it to the 2007 NBA Finals and has fueled hope that the Cavs can end Cleveland's 45-year drought without a major championship in any sport.
The Cavs have the second-best winning percentage (.780) in the Eastern Conference, and the best home record (23-1) in the NBA despite Sunday's loss to the Lakers and still haven't lost two in a row all season.
And now they have James and Williams headed to Sunday's game in Phoenix.
"My advice for a first-time All-Star is that that first shot feels like you're shooting a medicine ball, so try not to shoot an air ball," James said. "But Mo will be with me all weekend, so I'll guide him."