George Peasgood's family are "over the moon" that he will leave Tokyo 2020 with at least two Paralympic medals.
Peasgood, from Saffron Walden, secured a silver in the men's PTS5-category para triathlon in Japan on Saturday (August 28) with a 58:55-minute swim, run and cycle.
The 25-year-old athlete also secured a bronze in the men's C4 road time trial on Monday.
He will be back in the saddle for the men's cycling road race on Friday (September 3).
Peasgood's father, David, said he could not be prouder of his son's achievements this summer.
David said: "It's an honour - Teresa (George's mother) and I are over the moon.
"I've got nothing but admiration for him.
"We brought family and neighbours over to watch the events overnight - his brother cycled from Scotland to Saffron Walden to watch it with us.
"We have all done triathlon in our family. Teresa has run around 30 marathons.
"We know that competing at Paralympic level is really hard, and that's been harder to manage this year for all the athletes.
"We're very proud."
On Saturday, Peasgood led the swim but was overtaken in the cycle by Rio 2016 champion Martin Schulz, who eventually secured his second Paralympic win.
In the cycle, he secured bronze behind Slovakian duo Patrik Kuril and Jozef Metelka.
David said: "The cycling is his greatest love, but triathlon is the main focus.
"To get the silver in the triathlon and to be up alongside and beating world champions is very good.
"We always knew it was going to be close.
"George will be the first to admit that it's a team effort with support from British Tri.
"None of that would be possible without National Lottery funding either.
"The support we've had from people has been really phenomenal."
Peasgood is the 1,000th Team GB and Paralympic GB medallist since National Lottery funding was introduced in 1997.
Peasgood's sister-in-law Alison took silver in the para triathlon (visually impaired category) in 2016, missing out on a medal by one position in this year's games.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here