Title fight

In 1981, Tillis fought "Hercules" Mike Weaver for the WBA World Heavyweight title. After a strong start, Tillis tired. The fight would become famous for trainer Angelo Dundee imploring Tillis to do something, asking the fighter, "Do you want to be a bum all your life?" Ultimately, Tillis lost a close points decision.

In June 1982, Tillis came off the floor to outpoint the hard-hitting legend Earnie Shavers. He blew that momentum only a few months later, being upset by undefeated contender Pinklon Thomas, who was a late substitute, via an 8th-round knockout loss. In November 1982, Tillis fought former amateur rival Greg Page for the USBA Heavyweight title. He knocked Page down in the 2nd round, but again tired and was the victim of another eighth-round knockout loss. Thomas and Page would go on to win different versions of the world title.

Downward spiral

Having scored four wins, Tillis challenged future two-time world champion Tim Witherspoon in September 1983, for the vacant North American Boxing Federation title. Tillis was shockingly bombed out in one round, apparently slipping on a wet spot in the ring as Witherspoon hit him. After the fight, Tillis' trainer Angelo Dundee left him and advised him to retire, as he had just suffered his third defeat in thirteen months.

Tillis got a new team and put together four wins in 1984, before challenging Carl Williams in a world title eliminator. Having decked Williams twice in the opening round, Tillis tired and was outpointed. In 1985, under the guidance of trainer Drew Bundini Brown, he fought Joe Frazier's son and top contender Marvis Frazier. In a recurring theme, he had Frazier down in the second round, but again ran out of gas and was outpointed. A few months later, he traveled to South Africa to fight hard-hitting ex-champ Gerrie Coetzee. Tillis lost a unanimous decision, but sent Coetzee to hospital with stitches and missing teeth.

Stamina issue

After extensive medical examination, Tillis' strange recurrent fatigue midway through fights was found to derive from a severe allergy to the classic fighter's diet of milk and eggs. A doctor provided Tillis with a more suitable diet, in the training for his upcoming fight with Mike Tyson, a red-hot prospect with a 19–0 (19 knockouts) record. Tillis appeared to be a new man, as he exchanged with Tyson and gave the future two-time champion a very tough fight. Although ultimately outpointed, he was the first person ever to take Iron Mike to the distance. Surprisingly, Tillis' heart and will to fight has been questioned quite frequently by boxing analysts, even his co-manager Beau Williford told to the press the night before the fight considering that James was on a three-times-in-a-row losing streak, that his professional career as a boxer would be ended most likely if stopped by Tyson. Trainer Angelo Dundee, who worked with Tillis for the Weaver fight and some subsequent fights, finally gave up his job, he said: "James had no spirit to fight." In the pre-fight interview he told the ESPN staff that he found that spirit. To prove Dundee was wrong, Tillis violated almost all the Dundee "No-Nos" in the Tyson fight:^[1]

• Fought out of the squared-up stance, instead of the closed sideway stance.
• Sometimes fought with both hands down.
• Switched to southpaw and back to orthodox.
• Lead with his right hand.
• "Left-hooked with a hooker."
• Got tangled in wild exchanges.

Culminative moment of the fight came at 2:45 of the fourth round, when Tillis charged at Tyson with a leaping left hook, missed, and went off-balanced while pivoting on his left foot. Tyson slipped the punch and promptly switched to orthodox, throwing a leaping left hook of his own that landed right to the Tillis' chin, Tillis went down immediately. Tillis got up quickly at the count of "Two." That was the only knockdown during the entire fight, it cost Tillis a point, and subsequently a round on all the three judges' scorecards, and eventually the fight, which otherwise would have been ended a draw.^[2]

Initially, the crowd was rooting for Tyson, but in the later rounds it turned somewhat against Tyson due to him being unable to knock Tillis out, and after the ring announcer Paul LeFlore announced the judges' decision, pronouncing Tyson as the winner by a unanimous decision, the crowd booed wildly when referee Joe Cortez raised Tyson's hand. Being interviewed by the ABC Sports Network staff, Tyson himself said he just "fought a guy who was up for this fight, in the greatest shape in his life."^[1]

The new Tillis was short-lived, however, as he traveled to Australia and lost a decision to veteran Joe Bugner. In 1987, he was upset in eight rounds, as underdog (and regular Tyson sparring partner) Michael Williams came off the floor to stop Tillis. Later in the same year, he was stopped in five rounds on cuts by future champ Frank Bruno in London, and then knocked out in 10 rounds by hard-hitting Johnny DuPlooy in South Africa.

Having failed to secure a rematch with Tyson in 1988, this time for the undisputed heavyweight championship, he made one last attempt at the big time. Tillis was brought in to fight reigning cruiserweight world champion Evander Holyfield, who was making a high-profile move into the heavyweight ranks. Holyfield outpunched Tillis in five one-sided rounds.

Tillis resurfaced in 1991. However, his days even as a journeyman appeared over, as hard-hitting (and future WBO World Champion) Tommy Morrison stopped him out in one round.

Semi-retirement

Tillis fought on and off until 2001. Although he still was able to outpoint former top-flight amateur Craig Payne, a 39-year-old Tillis was stopped in six rounds by Cliff Couser in 1996.

Tillis fought his last fight in 2001, losing to clubfighter Rob Calloway when he was 44 years old.

Honorary Sign

On September 22, 2017, Tillis was honored by the city of Tulsa with honorary signs renaming a section of E. Virgin St "Quick Tillis Way" from N. Garrison Ave – N. Frankfort Ave.