Postpublished at 20:16 BST
You're not the only one, Jos.
I'm off for a lie down. Here's Ffion Wynne to take you through South Africa's glorious victory/chase.
England post incredible 304-2 - their highest T20 total
Salt hits unbeaten 141 from 60 balls - an England T20 record
Reaching ton in 39 balls is also the best by an England player in T20s
Buttler falls for 83 (30) after stunning 126-run stand with Salt
England v South Africa, second T20, Old Trafford
Proteas 1-0 up in three-match series
Listen to BBC Radio 5 Sports Extra commentary at top of page
by Matthew Henry
You're not the only one, Jos.
I'm off for a lie down. Here's Ffion Wynne to take you through South Africa's glorious victory/chase.
"300? I never thought I'd see that," says Jos Buttler.
Dawid Malan
Former England batter on TMS
Phil Salt deserves the applause. What an innings.
Everyone is so elated for him.
What a feeling to walk up those stairs and be surrounded by those lads high-fiving him.
It's only two to finish.
Harry Brook pushes Phil Salt forward to walk off on his own.
He finishes 141 not out from 60 balls - the highest score made by an England player in T20 internationals.
Dawid Malan
Former England batter on TMS
The crowd are on their feet as if someone has scored a match-winning hundred.
Can they finish it with a six?
Dawid Malan
Former England batter on TMS
Absolutely phenomenal.
Three hundred runs in a T20.
Who would have thought?
Kieran Parmley
CricViz analyst
That's the first time a side has reached 300 in a T20I between full member nations - India came closest previously, scoring 297-6 against Bangladesh in Hyderabad, 2024.
Oh and it's another no-ball!
There it is!
ENGLAND BECOME JUST THE THIRD MEN'S TEAM TO REACH 300 in T20IS.
Only a single.
All of Old Trafford is muttering for Harry Brook not to mess this up.
Phil Salt flicks over the ropes!
They're going to do it.
Phil Salt misses the free-hit as Rabada beats him with a slower ball.
It's another no-ball from Kagiso Rabada!
Good fielding form Kwena Maphaka but Harry Brook still gets back for three.
Dawid Malan
Former England batter on TMS
Even with the field set and a perfect ball for it, Harry Brook's found a way.
Smashed by Harry Brook. He's tried a lot of scoops and flicks but this is just noughties thrashing.
Salt 133, Brook 31
Marco Jansen finishes with 0-60 from four overs.
England need 16 from the last to break 300. Harry Brook will be on strike and Kagiso Rabada is going to bowl.
Dawid Malan
Former England batter on TMS
It feels like every single for South Africa is a win at this point...
This is some sensational fielding from Tristan Stubbs which denies Harry Brook a four.