ATLANTA -- Sue Bird jumped into Lauren Jackson's arms to celebrate the Seattle Storm's second WNBA championship and admitted that, after six years of waiting, this title was sweeter than the first.

"I'm going to be smiling for a long time," Bird said after the Storm completed their undefeated march through the postseason, beating the Atlanta Dream 87-84 on Thursday night for a three-game sweep in the WNBA Finals.

After losing in the first round of the playoffs five straight years following their first title, Bird, Jackson and the Storm are champions again.

"I guess now I can be honest," Bird said. "Losing in the first round has been terrible. It's something I took personally and something a lot of us took personally. ... I judge myself by winning, so to not win in five years really, really hurt."

The Storm made up for the long gap between titles by dominating the 2010 season. Seattle was 28-6 during the regular season -- tying the league record for wins -- before sweeping each of its three postseason series.

Bird and Jackson are the only players remaining from the Storm's 2004 title team.

"I think the roads have been completely different," said Jackson of the two championships. "After the last six years, it definitely has taken a long time to get here."

Jackson, who had 26 points in each of the Storm's first two wins in the series, had 15 points and nine rebounds and was selected MVP of the Finals.

Swin Cash scored 18 points to lead a balanced offense as Seattle overcame 35 points by Atlanta's Angel McCoughtry.

The Dream star, who set a WNBA playoff record with 42 points in the Eastern Conference finals clinching win over the New York Liberty, tried to rally Atlanta with nine points in the final 2:30. But McCoughtry and Coco Miller missed 3-pointers in the final 6 seconds, setting off a celebration by Seattle's players.

The Dream rallied in the final minute after trailing 82-70.

McCoughtry's three-point play with 46 seconds remaining cut Seattle's lead to 85-80. Seattle's Tanisha Wright missed two free throws and McCoughtry was fouled by Cash while missing a 3.

McCoughtry made two of three free throws to cut the lead to three points with 31 seconds remaining.

Bird dribbled away the shot clock before missing a shot to set up a basket by Atlanta's Iziane Castro Marques with 6.9 seconds left. McCoughtry immediately fouled Camille Little, who made two free throws to give Seattle an 87-84 lead.

McCoughtry missed a 3-pointer but the rebound went to Atlanta before Coco Miller also missed a last-second 3.

"I felt like the game was slipping away," McCoughtry said. "I felt like I needed to do something about it.

"I wish I had made all three of those free throws. That might have made a difference."

Atlanta reached the Finals in its third season and two years after setting a WNBA record with 30 losses.

"I think we have grown up quite a bit this season," Atlanta coach Marynell Meadors said.

"Maybe another minute on the clock might have made a difference in the outcome of this game and the same thing with the two games in Seattle."

Each of Seattle's starters scored in double figures.

Bird had 14 points and seven assists. Little had 15 and Wright had 13.

The Storm became the first team to win the championship without a postseason loss since the Los Angeles Sparks went 6-0 in 2002, when the Finals were a best-of-three series.

The sweep wasn't easy. The Storm won the first two games in Seattle by a combined margin of five points and struggled at times against Atlanta's relentless defense in the decisive Game 3.

"They really made it difficult for us to have success in each game," Seattle coach Brian Agler said.

The Dream led 59-53 late in the third quarter before Seattle took control with a 16-1 run, including the first basket of the fourth.

Castro Marques scored 21 points for Atlanta, Coco Miller had 12 and Erika de Souza added 10 points and 14 rebounds.

A fastbreak basket by McCoughtry gave the Dream the six-point lead before the Storm scored 14 of the last 15 points of the third quarter.

Wright's 3-pointer sparked Seattle's 10-0 run to open the game. The Storm kept the lead until Kelly Miller's 3-pointer with 2:02 remaining in the first half gave Atlanta a 41-39 lead.

The Dream shot 6 for 9 on 3s in the half, including a long jumper by McCoughtry that gave the Dream a 44-43 halftime lead.

Assistant coach Carol Ross and McCoughtry drew technical fouls for separate incidents in the first period.

The Finals attracted attention from Atlanta's other professional team.

The NBA Atlanta Hawks had a large turnout for the game, including Joe Johnson, Al Horford, Marvin Williams, Jeff Teague and Jordan Crawford. Also attending the game were John Abraham of the Atlanta Falcons and former Falcons coach Dan Reeves.