Born in Elizabeth, New Jersey, Blazejowski is the daughter of Leon and Grace (John) Blazejowski. She resides with her family in Nutley, New Jersey.
Using a jump shot patterned after what she saw in televised professional games, Blazejowski became one of the greatest scorers in the history of women's basketball, although she didn't begin serious competition until her senior year at Cranford High School in Cranford, New Jersey.
At Montclair State College in Montclair, New Jersey, the 5-foot-10 (1.78 m) forward was a three-time All-American, from 1976 through 1978. Blazejowski won the inaugural Wade Trophy as the nation's finest collegiate woman player in 1978. She led the nation in scoring with 33.5 points per game in 1976/77 and 38.6 points per game in 1977/78. Blazejowski scored 40 or more points in each of her last three games, including the semifinal loss to eventual champion UCLA. Sports Illustrated would call her, "the most relentlessly exciting performer in the history of women's basketball". She set a Madison Square Garden record for either sex with 52 points in a 1978 game against Queens College. Similar to all-time men's collegiate scoring record holder, Pete Maravich, "The Blaze" played during an era without the three-point shot.
After finishing her college career she played two seasons of AAU basketball with the Allentown, Pennsylvania, Crestettes. She often scored over 40 points in a game, and led the team to the semifinals both years, and once to a second-place finish. The leading scorer on the national team that won the 1979 world championship, she was chosen for the 1980 U.S. Olympic team, but her hopes for a gold medal were crushed after the U.S. boycott of the 1980 Summer Olympics.
Only an alternate on the 1976 Olympic team, she led the 1977 World University Games team in scoring and had 38 points in a losing effort against the Soviet Union.
Blazejowski traveled to San Juan, Puerto Rico to take part in the 1979 Pan American Games. The USA team won their first five games to advance to the gold medal game, but faced Cuba in the final, and lost 91–86 to take the silver medal. Blazejowski scored 10.2 points per game.
Blazejowski was named to the team representing the USA at the 1979 World University Games, held in Mexico City, Mexico. The USA team won all seven games to take the gold medal. The USA team played and beat Cuba twice, the team that had defeated them at the Pan Am games. Blazejowski was the leading scorer for the USA team, with 18.4 points per game.
The National team representing the USA had not won a World Championship since 1957. In 1979, the World Championships were held in Seoul, South Korea. Blazejowski was one of the twelve player squad. In the opening game against host South Korea, the USA team was upset, despite 23 points from Blazejowski. The USA team then faced Italy, and had a close call, winning but just two points 66–64. In the final game, the USA faced Canada, who had not lost. With the USA 4–1 record, the USA did not simply need to win, but need to win by more than 13 points to secure the gold. The USA ended up winning the game by 16 points, thus securing the gold with only three points to spare. Blazejowski was the leading scorer for the USA team with 18.7 points per game.
Blazejowski was named to the team representing the USA at the William Jones Cup competition in Taipei, Taiwan. The USA team won all six games en route to the gold medal. Blazejowski was named to the Jones Cup All-Tournament Team.
Blazejowski was named to the team scheduled to represent the USA at the 1980 Olympics, but the USA chose not to participate in the Olympics that year.
In 1980, Blazejowski became the highest-paid player in the Women's Pro Basketball League, signing a three-year contract for a reported $150,000 with the New Jersey Gems. However, the league folded after her first season, effectively ending her playing career.
After serving six years working in the front office of the National Basketball Association, Blazejowski was named Vice President and General Manager of the WNBA's New York Liberty on January 7, 1997. On February 15, 2008 it was announced that Blazejowski was promoted to President of the New York Liberty. On September 20, 2010, the New York Liberty announced her contract would not be extended. On February 22, 2011 it was announced that Blazejowski was hired as Associate Vice President for University Advancement at Montclair State University, rejoining her alma mater.