After his school friend Brad Cain notified Siaki that the WCW Power Plant was holding tryouts in early 1999, Siaki attended the tryout and was awarded a WCW developmental contract. He graduated after seven months and wrestled his first televised match on WCW Saturday Night against Allan Funk. Siaki largely appeared on Saturday Night and faced other Power Plant graduates, though he did make several appearances on Thunder and Nitro. Siaki eventually left WCW, unhappy with the way he was being utilized. Siaki moved on to the Urban Wrestling Alliance in California, where he was known as "Money". After nine months, the UWA folded and Siaki joined Turnbuckle Championship Wrestling where he received further training from the TCW owner, Dusty Rhodes.
On June 19, 2002 Siaki debuted on the first Total Nonstop Action Wrestling pay-per-view as one-third of The Flying Elvises with Jimmy Yang and Jorge Estrada. The Elvises were a comedy heelstable who impersonated Elvis Presley. The Elvises eventually split, with Siaki defeating Yang in a singles bout on August 21, 2002. Siaki now heel, went on to join Vince Russo's Sports Entertainment Xtreme a faction that tried to take over TNA. There he was then given a valet, Desire, a fellow TCW graduate, and earned the nickname "The Ace in the Hole". On December 11, 2002 Siaki defeated Jerry Lynn for the TNA X Division Championship. He held the belt until February 12, 2003 when he lost to Kid Kash. In July 2003 Siaki began a feud with D'Lo Brown, who he defeated in a Casket match. In October 2003 he formed a tag team with Ekmo, which split when Ekmo began working for All Japan Pro Wrestling. Siaki eventually became a face, and in April 2004 he and Simon Diamond began feuding with Glenn Gilberti and Johnny Swinger. After Siaki and Diamond were victorious in a tag match, their opponents were forced to wear Irish and Samoan native dress respectively, punishing Gilberti and Swinger for the ethnic jokes they had made in the preceding weeks. Siaki formed a tag-team with Apolo. On April 24, 2005 at TNA Lockdown he and Apolo defeated Lance Hoyt and Chris Candido in a steel cage tag match. Candido died four days after this match due to a blood clot brought on by a broken leg he suffered in the match. Throughout mid-2005 Siaki and Apolo feuded on a casual basis with The Diamonds in the Rough. In December 2005, Siaki's contract with TNA expired, and he declined to re-sign, instead leaving the promotion on good terms.
In late December 2005, Siaki signed a contract with World Wrestling Entertainment. He debuted in the WWE developmental territory Deep South Wrestling on February 2, 2006, suffering a minor injury in the process. On February 23, 2006, Sonny returned to Deep South Wrestling as a heel having a match with Damian Steele. Going by the moniker "Cocky Siaki", he and Eric Perez would win the Deep South Tag Team Titles on November 30, 2006. He then began teaming up with Afa Anoa'i, Jr. Both Siaki and former partner Eric Perez were working Raw house shows in March but Siaki suffered a back injury during that tour which left him out of action for 1 month. Siaki continued to tag with Afa Jr. in Deep South until it closed in April 2007.
Siaki then re-debuted with Afa, as The Samoan Fight Club, in the new development territory, under the World Wrestling Entertainment name, Florida Championship Wrestling. On September 15, 2007, it was reported that Siaki had been released from his developmental contract. Three days after the release, Siaki issued a statement saying that he has had some "personal issues" at home and that his focus was on his family right now, not wrestling.
Retirement
On September 17, 2008, Siaki retired from professional wrestling because he planned to donate one of his kidneys to his dying brother, Bernard. Siaki would only have one kidney remaining, and thus the doctor told him he could not wrestle anymore, effectively ending his ten-year career.
Personal life
He currently resides in Atlanta, Georgia and has a daughter. After retiring from professional wrestling Siaki began working for UPS. Siaki appeared on an episode of "Family Feud" with his family.