The former Australia international insisted that the third and final Test was there for the taking with the tourists 47 runs ahead going into the third day at Trent Bridge here Sunday.
England lead the series 1-0, with Sri Lanka having posted below par first-innings totals in all three Tests.
Moody demanded that his top order give Muttiah Muralitharan enough runs to bowl at to help them square the series in what could be the legendary off-spinner's last Test in England.
"Now is the time to strike," Moody told reporters after stumps on Saturday.
"It's there for the taking if we're prepared to knuckle down and do the hard work. We're overdue a decent total from our top order. The guys recognise that at times, they have let themselves down and the side too.
"Sunday's a great opportunity for them to put their hands up, make amends and get us a decent total. It would be nice for the attack to have something on the board to bowl to on the fourth or fifth day."
Sri Lanka were 45 for one with Upul Tharanga was 17 not out and Kumar Sangakkara 22 not out at stumps on Saturday. They lost Michael Vandort for five after the left-hander was bowled off the inside edge by Matthew Hoggard.
"We're in the driving seat because we've got the bat and nine wickets in hand but we've still got a lot of hard work to do," Moody said.
"We need to bat well in the first session -- that's going to be the key because England are going to throw everything at us. If we're still batting at the end of Sunday, I'll feel very comfortable going into the fourth day.
"We've come over here to win. We haven't played the most consistent cricket but we've got a chance here to rectify a few things."
Moody praised "wild and wonderful" quick bowler Lasith Malinga, who unnerved the hosts with his unorthodox 'slingshot' deliveries on Saturday.
He dismissed number three batsman Alastair Cook and finished off England's innings by having tailender Jon Lewis caught by Tillakaratne Dilshan.
"He's a unique bowler," Moody said. "He's not going to get his wickets through line and length and patience, which is the traditional way of taking wickets. He's wild and wonderful.
"Thankfully, I don't have to face him -- and I won't be volunteering to jump into the nets and attempt to."
England were bowled out for 229 earlier Saturday, a first innings deficit of two runs, with Paul Collingwood top-scoring with 48. He grafted hard for his runs, facing 184 balls in more than three-and-a-half hours in the sun at the crease, hitting one six.
Collingwood insisted England fancied their chances of sealing their first series win since last year's Ashes triumph at home to Australia.
"If we get a quick wicket we can get two or three and keep them down to a reasonable target," he told reporters. "We just need partnerships in the second innings. We've got a lot of talent out there and we'll be right up for it."
Regular England captain Michael Vaughan is playing his way back to form with his county Yorkshire following a knee injury.
Collingwood knows that either he or Cook is likely to make way should the batsman return for the four-match Test series against Pakistan, which begins on July 13 at Lord's.
But the all-rounder insisted he was not going to let it distract him.
"I know Vaughan's going to come back in -- I'm not silly, I'm realistic about the situation: there's probably a couple of players that are going to lose their place," Collingwood said.
"All you can do is make it as difficult as possible a decision for the selectors. But all my concentration is on doing well for the team and not on the personal stuff."
England's Marcus Trescothick was off the field for Saturday's final session with a migraine but a team spokesman said he expected the opening batsman to be fit on Sunday.