Champion Allison lived up to his name after producing a stunning comeback to advance to the 400 metres final at the World Championships on Wednesday, as fellow American Michael Norman stormed to the fastest finish in the semi-finals.
World record-holder and two-time world champion Wayde van Niekerk appeared to have a comfortable lead heading into the final 100 metres before Barbadian Jonathan Jones surged forward, running shoulder-to-shoulder with the South African.
But it was Allison, the second-fastest this year behind Norman, who recovered from about a metre back to sneak across the finish first, with van Niekerk, the Rio Olympic champion, holding on for the second automatic qualification spot.
"It is the challenge of doing this 400 (metres) and not having as many races in (the) legs as I would love to have by now," said van Niekerk, who is back in form after missing the final at the Tokyo Olympics last year.
"It is a learning process in every race. I am listening to my body and executing that way."
Trailing Matthew Hudson-Smith off the final turn, Norman accelerated down the final straight, inching past the Briton to win in 44.30 seconds, as Jamaican Christopher Taylor produced a speedy finish to advance as a fast loser.
"I felt like I kind of fell asleep in the last 50 (metres)," said Norman, who suffered a hamstring injury in Doha and failed to reach the podium in Tokyo. "I had to work hard coming down the home straight ... It is going to be a competitive race. It is all I can ask for."
Kirani James of Grenada pulled away from a tight pack down the final straight to win his heat in 44.74, with American Michael Cherry, who finished just off the podium in Tokyo, losing his strength in the final metres and failing to advance.
"There is a lot of talented guys out there," said James, the Olympic champion at London 2012. "I am just happy to be back in the moment."
Jeruto storms to steeplechase gold
Norah Jeruto delivered a devastating display of front running to win the world 3,000 metres steeplechase title in a massive championship record, earning gold for Kazakhstan having switched allegiance from Kenya earlier this year.
Jeruto clocked eight minutes, 53.02 seconds, the third-fastest time in history and more than five seconds better than Beatrice Chepkoech’s 2019 winning mark.
Werkuha Getachew set an Ethiopian record of 8:54.61 for silver, ahead of compatriot Mekides Abebe, who worked hard to rejoin the lead group and was rewarded with a personal best of 8:56.08.
Bahrain’s Winfred Mutile Yavi, fastest in the world this year, was right in the mix for a medal but had a terrible water jump on the final lap and lost all momentum to finish fourth for the second successive World Championships.
Feng delivers to claim discus title
China's Feng Bin put up the performance of her life to stun the women's discus final as Olympic champion American Valerie Allman settled for bronze.
Feng won off of her 69.12-metres opener, a personal best and her strongest performance of the season by a wide margin, as Croatia's two-time Olympic champion Sandra Perkovic secured the silver in a 68.45-metres second attempt.
With the home crowd urging her on, Allman rocketed the discus across the field on her third throw and she jumped with excitement but it was marked far short of Feng's effort, and she fumbled her final try for 51.41.
Feng whipped across a final throw of 64.62 before thrusting her arms into the air, having completed the massive upset and secured China's first gold in the event since Li Yanfeng in 2011.
Reigning champion Yaime Perez of Cuba could not find her power, finishing seventh with a best throw of 63.07.
While it was the first major title for Feng, a medal felt all too familiar around Perkovic's neck after two world titles, a bronze in Doha and a previous silver in 2015.