London - Aries Merritt's remarkable comeback from a kidney transplant two years ago continued on Sunday as the world record holder reached the 110 metres hurdles final at the world championships.
The 31-year-old American, who received a kidney from his sister LaToya days after taking bronze in the 2015 world final, finished second in his semi-final behind Hungary's 2016 European silver medallist Balazs Baji.
However, Merritt seemed little concerned by not winning, giving a broad grin, ahead of focusing on adding the world crown to the Olympic gold he won on the same London track in 2012.
Merritt - whose form has improved though the season as he won at the Diamond League meeting in London last month - explained that he hadn't gone full pelt due to a concern over his hamstring.
"I performed pretty well," said Merritt.
"I wasn't as aggressive at the hold.
"I felt a bit of tightness in my lead hamstring in the warm up so I just gradually warmed up for this race to loosen it up and it did. It is all fine.
"I like to be cautious. I don't want to injure myself so I was conservative. But it was solid."
Merritt will have to get past Jamaica's Omar McLeod, the man who succeeded him as Olympic champion and who has stated he wants to break his rival's world record at the championships.
McLeod - whose mother was watching from the stands - timed 13.10sec in winning his semi-final, getting the better of Frenchman Garfield Darien.
McLeod said he was a man on a mission, determined to make up for his sixth placed finish in the 2015 world title.
"When I competed at the 2015 Worlds, that was a learning curve for me. I made the finals," said the 23-year-old.
"Now in 2017 I kind of want a revenge for 2015 and just 'do me'.
"I am always confident. I am getting better and better.
"I am not limiting myself, so if it (the world record) happens it happens," added McLeod, who may also feature in Jamaica's 4x100m relay team.
Both reigning champion Sergey Shubenkov and Spain's Cuban-born Olympic silver medallist Orlando Ortega went through from that semi-final as the two fastest losers.
Barbados's Shane Brathwaite won a thrilling second semi-final - which saw the first four separated by just two hundredths of a second - recording a season's best of 13.26sec ahead of Jamaica's Hansle Parchment.
The two unlucky sprinters to miss out on the final were American Devon Allen, primarily an American football wide receiver for his university, and Britain's Andrew Pozzi who had looked good for a spot in the final when he led with two hurdles remaining.
But the 25-year-old European indoor champion was overtaken by the other three after clipping the penultimate hurdle.