Jakob Ingebrigtsen completed a golden double by capturing the men's 1,500 metres title on the final day of the World Indoor Athletics Championships on Sunday, a day after the Norwegian claimed the 3,000m crown.
Victory in three minutes 38.79 seconds meant Ingebrigtsen also matched the feat of Ethiopian great Haile Gebrselassie who won the double at the 1999 indoor worlds in Maebashi, Japan.
The 24-year-old Ingebrigtsen had warmed up for the global meeting with a similar effort at the European indoors in Apeldoorn, in the Netherlands, earlier this month.
"Of course this is something special," said Ingebrigtsen.
"It's very difficult to compare yourself against history and what others are doing. I'm only focusing on myself and feel good to have done a lot of preparations, and that was the main goal.
"It's not to do with something somebody else did before. I think I can do more, so I'll try to maximise that and grab the opportunity given to me."
The Olympic 5,000m champion was barely troubled after he took the lead midway and staved off Briton Neil Gourley, who claimed silver in 3:39.07, while American Luke Houser took bronze in 3:39.17.
Ethiopia's Gudaf Tsegay set a championship record of 3:54.86 en route to the women's 1,500m title, ahead of compatriot Diribe Welteji, who crossed the line in 3:59.30. Briton Georgia Hunter Bell completed the podium in 3:59.84.
"It wasn't an easy race, this was a fast time, so I'm very happy about that," Tsegay said.
"It was my training that led to this."
CHARLTON PREVAILS
Devynne Charlton of the Bahamas proved too good for an ultra competitive field in the women's 60m hurdles, as she crossed the line in a season's best of 7.72 seconds to retain her title.
Switzerland's Ditaji Kambundji scooped silver in 7.73 seconds and Jamaica's Ackera Nugent grabbed bronze in 7.74, with the top six all going under 7.80 seconds.
American Claire Bryant produced a personal best of 6.96 metres to win the women's long jump gold in the morning session at Nanjing's Cube. Switzerland's Annik Kalin was second with 6.83m and Spain's Fatima Diame finished third with 6.72m.
"If someone had told me that I would walk away from Nanjing with the title, I would thank them for that vote of confidence," said the 23-year-old Bryant.
"I didn't come in with expectations, I just wanted to enjoy the moment. Every part of this is so cool. I woke up at 4.45 a.m. this morning, I felt like it was Christmas morning and I knew there was something waiting for me.
"You can always surprise yourself in track, and I think that's what's so great about this sport. Seven metres is coming, for sure."
Australia claimed a one-two in the women's high jump as Nicola Olyslagers successfully defended her title by clearing 1.97m, winning on countback ahead of Eleanor Patterson.
Ukraine's world record holder Yaroslava Mahuchikh completed the podium with a leap of 1.95m, beating Serbia's Angelina Topic on countback.
Ingebrigtsen's compatriot Sander Skotheim claimed the men's heptathlon gold with a solid showing, finishing ahead of Estonian Johannes Erm and German Till Steinforth.
American Josh Hoey won his first world indoor title in the men's 800m in 1:44.77, while South Africa's Prudence Sekgodiso won the women's title with a world-leading 1:58.40.
Italy's Mattia Furlani won a fiercely contested long jump event with a leap of 8.30m, bettering Jamaica's Wayne Pinnock who managed 8.29m. Australia's Liam Adcock took bronze with 8.28m in his first indoor competition.
New Zealand's Tom Walsh collected his third indoor title and first in seven years in the shot put competition with a season's best throw of 21.65m.
The United States reigned supreme in the men's and women's 4x400m relays to cap off a successful meeting in which they topped the medals tally with 16 -- six gold, four silver and six bronze.