Stephen Miller won his third straight Paralympic gold medal with a new world record in the men's F32/51 club throw.
The 24-year-old from Newcastle, who has cerebral palsy, threw 33.53 metres in the second round to retain the title he won in Atlanta and Sydney.
Czech Radim Boles claimed silver and Algeria's Karim Betina took bronze.
Dave Weir won Britain's first track medal as he produced a late surge to take the bronze medal in the T54 200m while David Holding finished eighth.
Miller smashed the world record by more than seven metres, with all six of his throws good enough to take gold.
His mark of 33.53m eclipsed the previous record of 26m set by Boles in 2000.
The club, which is the Paralympics equivalent to the hammer, is a wooden object with a metal base that weighs just under half a kilogram and is thrown from a discus circle.
"I'm delighted with the new world record, but it was just a bonus," said Miller, who is also the secretary of Newcastle United's disabled supporters club.
"
I've trained all year for this and I'm speechless
"
T54 200m bronze medallist
David Weir
"I worked very hard for this competition and I was sure about my win. The throw was perfect.
"I'm very happy with a third Paralympic gold, I had faith in my ability."
Weir had come to his second Paralympic Games looking for his first medal at international level.
The 25-year-old did not disappoint as he recovered from a slow start to power off the bend and finish third in 25.55 seconds.
""It means the world to me," Weir told BBC Sport.
"I didn't think I'd get a medal but I went all out guns. I've got a bronze and I'm happy."
Finland's Leo Pekka Tahti won gold in 25.25 ahead of Dutch racer Kenny van Weeghel.
Things did not go so well for Darren Westlake in the T13 1500m as he finished back in 11th place.
Graeme Ballard, competing in his first Paralympics, came sixth in the T36 100m.
Earlier, there was disappointment for Britain's Pauline Latto as the Sydney silver medallist could only finish 11th in the women's F35-38 javelin final.
The event was won by Poland's Renata Chilweska.
But British duo Richard White and Lloyd Upsdell both advanced to Wednesday's final of the T35 100m.