Stuart Lancaster stressed the importance of England's crucial bonus point try after their opening win over Fiji at Twickenham.
Billy Vunipola struck in stoppage time for England as they picked up maximum points from a tough opening game.
"It's a big try in the context of this pool. They're absolutely invaluable, because it subconciously puts pressure on the opposition to go out there and get tries," said Lancaster.
The game saw the TMO used extensively by Jaco Peyper, much to the frustration of those watching in the stands at on television.
"We want to see accurate decisions," Lancaster said defending the process.
"It's part and parcel of the game and I think the players just get on with it."
England's growing concern over how Fiji were dominating the second half led to four substitutions by Lancaster after 50 minutes, a move he revealed wasn't initially planned but was certainly required.
"Geoff [Parling] got a mild stinger but he'll be fine. It wasn't pre-planned, but we felt the momentum was ebbing towards Fiji.
"We have a strong bench and we can trust them. In the context of the game it worked out about right."
Lancaster assessed the areas England clearly need to work on before facing Wales next Saturday, while also praising Anthony Watson for the way he handled Fiji's impressive winger Nemani Nadolo.
"We started well. A couple of scrum penalties we'll need to have a look at, we didn't get as much clean ball from the set-piece as we wanted.
"Fiji made it very difficult at the contact area and competed well at the breakdown. We needed to be more direct and I think we were in the last 20 minutes when we gave them more problems.
"We gave away penalties at the breakdown too not rolling away and we'll have to address those issues.
"We were too lateral in the first half and needed to be more direct. The guys who came on gave us a bit more direction.
"Nadolo was a real challenge. He's a star of the southern hemisphere and I thought Anthony did well. The kick was a great kick from Volavola and Nadolo took his try well. He's a phenomenal athlete and once Fiji get their offload game going they're hard to stop. Anthony did well, because he's a big, big man.
"Fiji will cause every team problems if I'm honest. They then have an eight-day break before playing Wales, who have a short turnaround after playing us.
"We need to improve. But if you said at the start for four tries and a bonus point I'd have absolutely taken that."
Reflecting on the opening ceremony, Lancaster hinted that the pre-game spectacle had a negative effect on England's preparations.
"The whole thing was phenomenal as an occasion for the players. We were a little early but Twickenham was rocking when we arrived.
"The boys were like caged animals really, normally we're out there warming up but obviously we had to sit in the changing room and that built up the nerves and meant it took a while for us to settle.
"We were pretty much hidden from it all really, which wasn't a bad thing I suppose."