ATLANTA -- In an intense game with major playoff-seeding implications, the Atlanta Hawks were down 12 to the visiting Boston Celtics in the third quarter. That's when Paul Millsap took over.

Millsap scored 31 points, grabbed 16 rebounds and sparked a furious second-half Atlanta rally to lead the Hawks to a 118-107 victory over the Celtics in the regular-season home finale at Philips Arena.

With two games remaining, the Hawks (48-32) have a one-game lead on the Celtics (47-33) for the third seed and 1 1/2-game lead over the Miami Heat and Charlotte Hornets. Atlanta finishes the regular season on the road, starting Monday at Cleveland and concluding Wednesday in Washington.

Boston wraps up the regular season at home against the Hornets on Monday and the Heat on Wednesday. The Hawks won three of four against the Celtics and own the tiebreaker should they finish with the same record.

The Celtics led 71-67 in a high-scoring, back-and-forth first half that featured nine lead changes. Both teams hit 10 3-pointers in the first half and combined to shoot 56.9 percent from the floor overall.

Atlanta point guard Jeff Teague had 16 in the first half. Marcus Smart came off the bench to score 14 in the first half, including four 3-pointers.

Boston's lead grew to 12 in the third quarter, before a 3-pointer by Kyle Korver - his first of the game -- was part of an 8-0 run for the Hawks. Millsap's 3-pointer capped the spurt that trimmed the Boston lead to 87-83 with four minutes left in the quarter.

Minutes later, Millsap banked in a straight-on 3-pointer and hit a layup in the final 45 seconds of the quarter to give the Hawks a 93-91 lead heading into the fourth quarter. Millsap had 13 in the third quarter.

Smart scored 19 points off the bench to lead six Celtics in double figures. Isaiah Thomas and Jae Crowder each finished with 16 points.

Teague added 24 points, including a big three-point play that put the Hawks up seven with three minutes to play. Kent Bazemore returned to the starting lineup after missing a game with a sore knee to score 21 points for Atlanta, which has won 12 of 15.

NOTES: Boston C Tyler Zeller scored a team-high 26 points in Thursday's win over Milwaukee, snapping PG Isaiah Thomas' 17-game streak of leading the Celtics in scoring. ... Boston coach Brad Stevens has said he doesn't plan to rest players in final week of season and has instead tried to find ways to reduce his players' minutes throughout the season. ... The Hawks have clinched a playoff berth for the ninth straight season, the longest active streak in the Eastern Conference. ... Atlanta F/G Kent Bazemore (sore knee) returned after missing Thursday's win over Toronto. ... The Hawks finish the season at Cleveland on Monday and at Washington on Wednesday. Boston wraps up the regular season at home against Charlotte on Monday and Miami on Wednesday.