Washington later served in the United States Navy as a helicopter mechanic[2] Despite having played one season of organized football, he enrolled at Chaffey College in Rancho Cucamonga, California and was an NJCAA All-American as a tight end.

[5] In his first professional fight, Washington knocked out Blue DeLong at the HP Pavilion in San Jose, California.

A month later in August, Washington defeated Gary Cobia via 1st-round TKO at the Fantasy Springs Casino in California.

[6] On June 8, 2013, Washington fought 40 year old veteran Sherman Williams (35-12-2, 19 KOs) to an 8-round unanimous decision victory at the Home Depot Center in Carson, California.

[15][16][17] Washington next fought in December 2014 against 39 year old journeyman Mike Sheppard (22-17-1, 9 KOs) at the Pechanga Resort & Casino in Temecula, California.

[18] On March 13, 2015 Washington went the 8 round distance, winning a wide decision of 78–71, 79–70, and 79–70, against 37 year old journeyman Jason Gavern (26-18-4, 11 KOs).

Washington had his best win to date in March 2015 when he beat longtime veteran Jason Gavern in a 10-round decision victory.

The fight was to take place on Premier Boxing Champions on Fox Sports 1 from the Little Creek Casino Resort, in Shelton, Washington.

Washington appeared to lose the last 6 rounds of the fight due to his running, holding and low punch output.

[24] Two days before the fight, the California State Athletic Commission conducted an eye exam, which Rivas failed.

[26] Washington threw three times the amount of punches and used his big size advantage to beat Chambers by an 8-round unanimous decision.

[30] On January 26, 2017, Washington became a front runner to land a fight against WBC heavyweight champion Deontay Wilder (37-0, 36 KOs) at the Legacy Arena in Birmingham, Alabama, on February 25 on Fox.

The bout was the most watched boxing match in the United States for 2017 until the Thurman-Garcia unification fight drew 3.74 million on March 4.

[38][39] On June 27, it was announced that Washington would fight unbeaten heavyweight contender Jarrell Miller (18-0-1, 16 KOs) on the undercard of Garcia-Broner at the Barclays Center in New York on July 29, 2017 in a 10-round bout.

Washington had a good opening round, but Miller took control landing power shots and causing heavy punishment.

Washington suffered his second consecutive stoppage loss and Miller fought for the first time in 11 months.

Stephen Espinoza, Showtime Sports general manager praised Miller and said he could soon feature on 'Showtime Championship Boxing' soon.

[45] After 11 months out, Washington returned to the ring on a Sunday edition of PBC on Fox Sports 1 on June 10, 2018.

The three judges scored the bout 98–91, 97–92, and 97–92 in favor of Washington, giving him the much needed win and snapping his 2-fight losing streak.

The fight would air live on FOX, as part of their new long term deal with PBC, on the undercard of Keith Thurman vs. Josesito Lopez.

In the eighth round, Washington caught Helenius with a long right hand, sending him straight to the canvas.