(My Sportsbook) - The eighth-seeded Atlanta Hawks attempt to pull off one of the biggest upsets in NBA playoff history, as they visit the top-seeded Boston Celtics this afternoon at TD Banknorth Garden in the decisive Game 7 of their first-round series.

The Hawks are trying to become just the second eighth seed to knock off a No. 1 seed in a best-of-seven series. It happened last year when the Golden State Warriors upset the Dallas Mavericks in six games, 4-2, in the first round of the postseason.

Two other eighth-seeded teams defeated a one seed in the first round of the playoffs. Denver eliminated the Seattle SuperSonics, 3-2, in the first round of the 1994 playoffs, while the New York Knicks knocked out the Miami Heat in five, 3-2, during the opening round of the 1999 postseason.

On Friday, Joe Johnson scored eight of his 15 points in the fourth quarter, as the Hawks forced a deciding seventh game in their Eastern Conference quarterfinal series with a dramatic 103-100 victory over the Celtics at Philips Arena.

Marvin Williams had 18 points, but saw limited time in the second half because of a sprained left knee for the Hawks, while Mike Bibby netted 17 in the win. Rookie Al Horford had 16 points, Josh Childress scored 15 and Josh Smith ended with 11 points for Atlanta.

Kevin Garnett finished with 22 points in the loss for the Celtics, who played without standout Paul Pierce in the latter part of the fourth quarter. Pierce fouled out with 4:44 left and totaled 17 points in defeat.

Williams is questionable because of his knee injury. He is averaging 12.2 points in the first-round series.

The winner of today's contest will meet the fourth-seeded Cleveland Cavaliers in the best-of-seven Eastern Conference semifinals.

Boston has lost two straight Game 7s. The Celtics are 17-5 all-time and 14-3 at home in Game 7s.

The Celtics lost their last Game 7 at home, as they were crushed by the Indiana Pacers, 97-70, on May 7, 2005 in the final contest of the first-round series.

Boston is attempting to win its first playoff series since defeating Indiana, 4-2, in round one of the 2003 postseason. The Celtics are 3-6 in their last nine contests when they have the chance to eliminate their opponent from the postseason.

The Celtics captured a playoff berth and the Atlantic Division title for the first time since the 2004-05 season. Boston finished with its highest number of wins (66) since the 1985-86 squad went 67-15 before winning the NBA title. With a 66-16 mark in the regular season, Boston collected 42 more victories than it did last season, when it finished with a dismal 24-58 record.

The young and surprising Hawks are back in the playoffs for the first time since the strike-shortened 1998-99 campaign. Atlanta battled all season and fended off both Indiana and New Jersey to finish with its best record in 10 years.

Atlanta's last playoff series victory was in the first round of the 1999 postseason. The Hawks defeated the Pistons, 3-2, before being swept by the Knicks, 4-0, in the East semis.

The Hawks are 0-3 in Game 7s against Boston, The Celtics defeated Atlanta, 118-116, on May 22, 1988 in Beantown in the decisive game of their semifinals series. The St. Louis Hawks lost two Game 7s to Boston in 1957 and 1960.

The Hawks' franchise is 2-7 all-time in Game 7s. The last time the Hawks won a Game 7 was in 1961 when the team called St. Louis home.

Boston is 5-0 all-time in the playoffs against the Hawks. The Celtics defeated Atlanta in the postseason in 1972, 1973, 1983, 1986 and 1988.