Nasser Hussain called the action of day four of the second Ashes Test at Lord's "brilliant, magnificent viewing", hailing Jofra Archer - who bowled a brutally quick spell to Steve Smith in the afternoon session - as an "absolute gem".
Hussain added that England could not win this Ashes series without Archer in the side, despite the fact that the 24-year-old is only making his Test debut in the game.
Archer took 2-59 in 29 overs as Australia were bowled out for 250 in their second innings, while he hit a top speed of 96.1mph during a fiery eight-over burst that saw him strike Steve Smith twice - first on the forearm and then a blow to the head, under his left ear, seeing him temporarily taken off the field.
Hussain, reflecting on the day as a whole as well as the battle between Archer and Smith, said: "It was incredible to watch. Brilliant, magnificent viewing.
"This is a batsman [Smith] who England haven't got a clue how to get out. Suddenly, a lad on debut - we keep forgetting this is Archer's first Test match - and he is running in, high-quality fast bowling, disturbing the best batsman there is in world cricket right now.
"It was so good, it's untrue. Smith got hit and he got taken off - there was real concern there - but he came back like the champion he is.
"Justin Langer [Australia head coach] said before the game 'let's see what he [Archer] is like coming back in his fourth or fifth spells', but in his fifth spell he came back and bowled a delivery at 96.1mph.
"His fitness, his stamina, there are absolutely no concerns about. And he has so many variations, so many different deliveries.
"My only concern looking forward is England captains going to him so often. James Anderson, Stuart Broad are not going to be around forever, and you want him bowling with the new ball, want him to work people over like Smith and then you're going to want him at the tail because he has that extra pace.
"How you handle Archer is going to be paramount going forward, as fast bowlers are like gold dust.
"Look after him, because this lad is an absolute gem. I'm going to say a big comment here, but if Archer didn't play in this series, England could not win the Ashes.
"He is that important. Coming into this game in the absence of Anderson, to have his firepower is incredible."
Smith, unbeaten on 80 at the time, was led off the field for further concussion testing before being cleared to return on the fall of the next wicket.
He would ultimately be dismissed lbw by Chris Woakes for 92, eight runs short of a fourth consecutive Ashes century in England, after a slightly frenetic second spell at the crease.
Hussain believes the punishment Smith took from Archer could have a lasting psychological effect for the remainder of the series.
"You've got to remember there are three and a half Test matches to go batting-wise, with the second innings too here," Hussain added. "The real interesting thing is what this does now for the rest of the series?
"The effect of that blow and that Archer spell on Smith; stories of Ricky Ponting, how he took on the short ball after he took a blow.
"Also, the knowledge now that Joe Root has, the captain thinking 'I've got something on him with this lad up my sleeve.'"
Woakes, who finally took Smith's wicket as he left a straight ball that trapped him in front of the stumps, reflected on the brilliance of Archer's earlier spell to Smith when speaking to Ian Ward at the close of play.
"That was serious, serious pace," the England seamer said. "Seeing the speeds come up on the board was no surprise really - it looked quick!
"I was down at fine leg and you don't normally get a good gauge of it from there, but even I could tell from down there that it was whistling through.
"The crowd, the atmosphere helped build it all up, and obviously bowling to a world-class player in Smith as well.
"It's never nice to see anyone get hit. We're not in the game to hurt people, though Ashes cricket is going to be played hard and tough.
"At the same time, you don't want anyone to be injured, by any means, and thankfully it looks like Steve is okay.
"Such a great player, it took something special from Jofra to get him out of his bubble. This series so far, he has been fantastic."
After Australia were dismissed for 250 in their second innings, England themselves struggled to 96-4 and a lead of 104 by stumps.
Woakes believes the morning session on the final day - Ben Stokes and Jos Buttler unbeaten on 16 and 10 respectively - will be vital to any hopes of the hosts forcing a victory.
"It's an evenly-matched game at the minute," Woakes added. "We're pleased that we're not batting last on that surface but, at the same time, we still need to build that lead - get enough of one to feel safe when going out there trying to bowl them out.
"The morning session is always key; if they get two early wickets, they'll feel on top, but if we bat well till lunch - build a partnership - we can get on top."
Watch day five of the second Test between England and Australia at Lord's from 10am on Sky Sports The Ashes.