On April 21, 1983, Dynamite and Tiger Mask met for the vacant WWF Junior Heavyweight Championship, but no winner was decided after the match ended up as a draw three consecutive times. On February 7, 1984, Dynamite captured the WWF Junior Heavyweight Championship. Although it was a WWF Title, it was primarily defended in Japan. He defeated Davey Boy Smith earlier in the tournament, and would go on to defeat The Cobra in the finals.
Dynamite Kid made his WWF television debut on August 29, 1984, where he and Bret Hart defeated Iron Mike Sharpe and Troy Alexander in a match eventually shown on September 15, 1984 on the Maple Leaf Garden broadcast. Dynamite would end up teaming with Davey Boy Smith as the British Bulldogs, while Bret would team with Jim Neidhart as The Hart Foundation, and it led to matches between the two teams that usually ended in No-Contests. On April 7, 1986, accompanied by Captain Lou Albano and Ozzy Osbourne, the British Bulldogs won the WWF World tag team title from Greg Valentine and Brutus Beefcake at WrestleMania II. Dynamite Kid was injured in December 1986 in a tag match in Hamilton, Ontario, Canada against Don Muraco and Bob Orton and several wrestlers including Roddy Piper, Junkyard Dog and Billy Jack Haynes would substitute for him when tag title defenses were made. While recovering in the hospital from back surgery, Billington would later recount that Bret Hart showed up and stated that Vince McMahon had sent him to get Dynamite's tag belt; Dynamite refused. Shortly after checking himself out of the hospital (against doctors' orders), Billington met with McMahon, who requested that the Bulldogs drop the tag titles to the team of Nikolai Volkoff and The Iron Sheik; Dynamite refused, saying that he would only drop the belts to The Hart Foundation.
McMahon acquiesced and at a TV taping on January 26, 1987, The British Bulldogs wrestled a match to drop the titles to The Hart Foundation; the match would air on the February 7 edition of WWF Superstars of Wrestling. The match itself was an odd sight, as Dynamite could barely walk due to back surgery, and thus needed to be assisted to the ring by linking arms with Davey Boy Smith; Dynamite was knocked out (kayfabe) by Jimmy Hart's megaphone early in the match, therefore avoiding his having to wrestle in the match. From that point forward, the Bulldogs would not be a top-tier team anymore, and while they would not become straight jobbers, they would mostly wrestle to double disqualifications, double countouts or time-limit draws against the top teams in the WWF. After getting into a real life backstage fight with Jacques Rougeau, the Bulldogs wrestled their last WWF match at the 1988 Survivor Series.