The Grizzlies had rallied from a 17-point third-quarter deficit and led 102-100 on Rudy Gay's dunk off an offensive rebound with 1:30 remaining.

But Barbosa sank his second 3-pointer of the game to give Phoenix a 103-102 lead.

After a pair of Steve Nash free throws, Mayo missed a straightaway 3-pointer with 6.9 seconds to allow Phoenix to escape with its ninth straight win over Memphis.

Amare Stoudemire scored 18 points, Boris Diaw added 13 and Nash had 12 points and six assists for the Suns, who have won five of their past six games overall.

Rudy Gay scored 20 and Marc Gasol finished with 15 for the Grizzlies, who were 1-3 on their four-game Western road trip.

Phoenix had an 82-70 lead heading into the fourth quarter before Mayo single-handedly carried the Grizzlies within a basket. Mayo scored 11 straight points, including a 19-footer with 8:42 to play as Memphis pulled to 87-85.

The Suns stretched the lead back to six, 93-87, only to see the Grizzlies tie the game 94-94 on Marc Gasol's three-point play with 4:22 to go. Hakim Warrick gave Memphis a 96-94 lead on a 22-foot bank shot with 3:48 left.

Barbosa put the Suns back ahead 100-98 on a 3-pointer from the right wing. Darko Milicic tied the game with a layup with 2:12 left before Gay gave Memphis its final lead.

Barbosa scored 10 straight points in the third and fourth quarters for Phoenix, including the Suns' first eight in the fourth. He was the only Phoenix player to hit a field goal between Diaw's layup with 3:37 left in the third and Raja Bell's 3-pointer with 3:28 to go.

Mayo had given the Grizzlies a 51-50 lead on a 3-pointer with 9:34 to go in the third quarter before the Suns pulled away.

Matt Barnes' 3-pointer started an 18-4 run over the next five minutes as Phoenix opened a 68-55 lead with 4:34 left in the period. Bell, Diaw and Nash also hit 3-pointers during the streak for the Suns, who finished 8-for-21 from beyond the arc.

Barbosa's layup with 54.5 seconds left gave the Suns their biggest lead, 82-65, and started his scoring streak.

Notes: Phoenix coach Terry Porter is 6-2 in his Suns career, the best start for a coach in franchise history. ... Suns guard Raja Bell missed the morning shootaround following the birth of his second child on Sunday. ... Suns forward Matt Barnes returned to the lineup after missing three games following the birth of two sons. ... Memphis had won four of five meetings before the current losing streak. The Grizzlies are 4-22 all-time in Phoenix and have not beaten the Suns in the Valley since November 16, 2005.