Karsten Warholm retained his men's 400 metres hurdles title on what proved to be a good day for defending champions at the World Athletics Championships.
Norwegian Warholm rounded out Monday's schedule in Doha by holding off American Rai Benjamin to triumph in a time of 47.42 seconds.
Muktar Edris also made it back-to-back world golds in the men's 5,000m, while Mariya Lasitskene went one better in the women's high jump, triumphing for an unprecedented third straight time.
Read: Annu Rani smashes national record, reaches final
There was a surprise in the women's 800m, however, as Uganda's Halimah Nakaayi prevailed - with pre-race favourite Ajee Wilson having to settle for bronze - while Daniel Stahl claimed gold in the men's discus.
As for the 200m, a number of high-profile names pulled out of the women's event but men's favourite Noah Lyles had no issues in progressing to the final.
THIS MEANS WAR!
While the time was not fast enough to threaten Kevin Young's long-standing world record of 46.78s, a mark set way back in 1992, Warholm still produced an impressive performance to reign again at the end of a long season.
The 23-year-old set the pace in the early going and remained clear of the field, with Benjamin unable to reel him in during the closing metres. Qatar's Abderrahman Samba rounded out the podium places.
Also read: Qatar's headache: Records galore, empty seats bear witness
"I actually felt my heart was going to stop. I thought I was going to die... but it's going to be worth it!" Warholm told BBC Sport in his post-race interview.
"Here I am - world champion. And I'm not dead either!"
Lasitskene created history as she once again ruled, in the process becoming the first athlete to win three successive world high jump titles.
The Russian, competing as an Authorised Neutral Athlete, wrapped up gold with a clearance of 2.04m at the first attempt, though she failed in an effort to set a new personal best at 2.08m.
Yaroslava Mahuchikh of Ukraine also made it over 2.04m at the third time of asking, the 18-year-old setting a world junior record as she claimed the silver medal.
DINA DAZZLES - LYLES ON TRACK
After a silver medal in the 100m on Sunday, Dina Asher-Smith set the fastest time in her heat in the women's 200m.
The British runner will have high hopes of claiming a gold after a number of leading contenders opted not to run at the distance, including Dutch defending champion Dafne Schippers.
Also read: Felix surpasses Bolt with 12th gold
Shelly-Ann Fraser-Pryce of Jamaica - who won gold in the 100m - was another leading name to withdraw, while Blessing Okagbare was disqualified after running out of her lane.
Lyles, meanwhile, laid down a marker by posting a time of 19.86s in the men's 200m. The American had silver hair for his heats on the previous day but will be out for gold in Tuesday's final. Ecuador's Alex Quinonez could be his main rival after impressing with a time of 19.95s.