England head coach Eddie Jones praised the impact of Sam Simmonds after the No8's two tries helped the defending champions to a commanding win over Italy in their Six Nations curtain-raiser.
The Exeter back-row, making his tournament debut, notched a second-half double as England swaggered to a seven-try victory in Rome.
Two tries from Anthony Watson and further touchdowns from Owen Farrell, George Ford and Jack Nowell saw Eddie Jones's men overcome a determined Italy, who had kept in touch until the final 20 minutes.
"We knew that they were going to hang in there," said Jones.
"But we ran away it in the end. The basis of the game — the scrum and the lineout — were good for us today. Sam Simmonds was in his element when the game opened up.
"He has so much gas he does his speed work with the backs. He gives us a great option at No8."
Simmonds, deputising at the back of the scrum in place of the the injured Nathan Hughes and Billy Vunipola, earned praise for his performance from the latter's Saracens teammate Owen Farrell.
"Sam Simmonds was brilliant," said the 26-year-old, who was deployed at inside centre.
"He's quick and powerful and we're pleased to have him in our squad."
Despite an early injury to Ben Youngs, England raced into an early 10-0 lead within 10 minutes thanks to two clinical finishes from Watson on the right wing.
The Red Rose attack bamboozled Italy's defence with well-executed wrap-around plays and decoy runners before unleashing Watson to score.
Two missed conversions from Farrell kept the Azzurri within touching distance and the home side did not back down from head coach Conor O'Shea's insistence that they would attack England.
On 20 minutes they pulled back to within three points after fly-half Tommy Allan capped a beautifully crafted try with a looping assist to winger Tommaso Benvenuti.
England hit back five minutes later when Farrell played a one-two with No10 Ford and converted his own score to spark the Stadio Olimpico's first rendition of the afternoon of Swing Low, Sweet Chariot. Allan then converted a penalty minutes before the break to reduce the deficit to 17-10.
Both sides had early second-half scores ruled out by the TMO before Simmonds burst free from the back of a maul to score his first international try on 53 minutes.
Mattia Bellini went over for an unconverted try to pull Italy within 12 points with 20 minutes remaining, yet it only sparked a final-quarter onslaught from England.
First Farrell returned the favour to Ford by setting him up for a try, before Simmonds accelerated through Italy's defence and substitute Nowell crossed over in the corner to clinch a 31-point victory that leaves the holders top of the table after week one.