Tucker scored 17 points, including two big baskets to stop a Dallas rally in the closing minutes, and the Suns helped eliminate the Dallas Mavericks from postseason contention with a 102-91 victory on Wednesday night.
Dallas was officially out a couple of hours later when the Los Angeles Lakers beat Portland 113-106. It's the first time the Mavericks (38-40) have finished outside the top eight in the Western Conference since 2000.
Nowitzki was a second-year pro the last time the Mavericks were home for the postseason. He was left to wait to see what happened later Wednesday with the Lakers' game in Portland.
"I mean, it didn't look good for two or three weeks," said Nowitzki, who had 21 points but was just 6 of 18 from the field. "It's not like we had unbelievable high hopes for it. It's not like our hopes were crushed tonight."
The Suns blew a 14-point lead in the first quarter and almost did it again in the fourth before hanging on to snap their longest losing streak in 16 years.
Phoenix led 85-71 early in the fourth quarter but was up by just four when Tucker put in a layup for a six-point lead after a shot by Luis Scola barely touched the rim as the shot clock expired.
Tucker, who also had 10 rebounds, grabbed a miss by O.J. Mayo on the other end, then hit a 3-pointer for a 98-89 lead with 1:01 remaining. Tucker, a 26 percent shooter from long range this season, was 3 of 4 from beyond the arc.
"We needed to score right there. We needed to answer back," Tucker said. "I got like three or four of them I should have had before that and didn't get them, so that one was huge."
Goran Dragic led the Suns with 21 points and 13 assists, while Scola had 11 points and a season-high 15 rebounds.
Phoenix, playing a night after losing at the buzzer in Houston when Jermaine O'Neal was called for goaltending on a tiebreaking 3-pointer by James Harden, also snapped a 10-game skid in Dallas dating to March 2007.
"I guess we underestimated them tonight and they came in here and got a win," said Shawn Marion, who led Dallas with 22 points and nine rebounds.
Phoenix took the lead for good with an 18-4 run in the third quarter. Dragic started it with a 3-pointer to break a 63-all tie, then had assists on a layup by Tucker and a 3-pointer from Markieff Morris.
The Mavericks went almost 5 minutes without a basket in the third quarter and another 4 minutes to start the fourth before Mayo hit a long jumper, but Phoenix pushed the lead back to 12 with help from free throws by Dragic after Mayo was called for a flagrant foul for throwing his shoulder into the Suns guard when he was driving.
Dallas shot 27 percent from the floor in the fourth quarter.
"Every time we've had a chance, we've laid an egg. Just not good enough," Nowitzki said. "This is a game we needed to have. We were the team that looked like we were on a back-to-back, not them. A terrible, terrible, disappointing loss."
The Suns led 51-41 at halftime after being up by 14 in the first quarter, but Dallas started the second half with a 12-2 run to get even.
Wesley Johnson scored 15 points in the second quarter to help the Suns rebuild a double-digit lead they lost when Vince Carter sparked a 12-0 Dallas run with a one-handed dunk off a miss by Nowitzki, who was 0 of 5 in the first quarter and took some practice shots before going to the bench at the end of the period.
Johnson, who didn't score in the second half, was 3 of 4 from 3-point range in the first half and the Suns, 29th in the NBA in 3-point shooting at 33 percent coming in, went 6 of 9 from beyond the arc in the second quarter.
Dragic had 11 points on 5-of-6 shooting in the first quarter to build the Phoenix lead, and the Suns' starting backcourt of Dragic and Johnson outscored Dallas starters Mike James and Mayo 33-8 in the first half, which ended with Phoenix leading 61-51.
"I think we gave a team that was playing for nothing life at the beginning," Carter said. "It was tough to break their rhythm after that."
Dallas coach Rick Carlisle got a first-quarter technical when C Chris Kaman was called for a foul after knocking over Dragic at midcourt when a dribbling Dragic stopped in front of him. Carlisle stepped onto the court to complain about the call, drawing a puzzled look from Dragic. ... Mavericks C Elton Brand missed his fourth straight game with a sore right calf, and Suns F Michael Beasley missed his second straight for the birth of his daughter in Phoenix. ... There was a brief delay in the fourth quarter when the scoreboards, game clocks and shot clocks went blank or reset. Turned out there was 4:20 remaining.