He grew up in Sammamish, Washington, and was drafted in the 28th round out of Eastlake High School in 2001 by the Cardinals. He played one year of baseball at Bellevue College (now simply Bellevue College) before signing with the Cardinals as a draft and follow. Prior to playing at Bellevue Community College Blake played several years under Bill Caudill for the Mercer Islanders and Fox Sports. After 2 superb seasons in the minors, he was named by Baseball America as the Cardinals' top prospect in 2003. However, injuries limited him to pitching in only 9 games in 2004 and 2005. However, he got right back on track in 2006 as he went 11–4 and with an ERA under 3 between the Palm Beach Cardinals and the Springfield Cardinals. In 2007, he played for the Memphis Redbirds and ended the season with a disappointing 4–13 record with an 5.28 ERA. And in 2008, he went 5–7 with a 6.09 ERA.
He made his major league debut on June 6, 2009, pitching 2 IP, giving up 4 runs, 3 hits including a home run, walking 1, and striking out 1. Despite this, his debut was looked at as positive because of his excellent pitch command. The Cardinals had high hopes for him in the future, as he was one of the organizations' better young pitching talents.
Hawksworth was hit in the face near his mouth by a line drive by outfielder Sam Fuld, and crumpled to the ground, in a game in September 2010. He left the field under his own power and was taken to hospital. The injury required approximately 20 stitches, and ended his season.
In two seasons with the Cardinals, he appeared in 75 games, starting 8 of them. His overall record was 8–8 with a 4.07 ERA.
On November 30, 2010, he was traded to the Los Angeles Dodgers for infielder Ryan Theriot. He appeared in 49 games for the Dodgers, all in relief, with a 2–5 record and 4.08 ERA.
Hawksworth began feeling tenderness and discomfort in his elbow during the offseason and underwent elbow surgery in early January 2012. This injury caused him to be placed on the 60-day disabled list at the start of the season. He began a rehab assignment in June but was shut down after a couple of appearances due to shoulder soreness. On August 23, he underwent arthroscopic shoulder surgery, which ended any chance he had to return in 2012 and the report from the team was that he might also miss the 2013 season as a result of the recovery period. On October 12, 2012 the Dodgers outrighted him to AAA and removed him from the 40-man roster. On October 17, he elected to become a free agent.
Hawksworth retired in February 2014.
His older sister Erin is a television sports anchor in Washington, D.C., and his grandfather Jack Poole was the head of the VANOC bid committee that brought the Winter Olympics to Vancouver.
After his baseball career ended due to injury, he became an assistant basketball coach at Eastlake High School.