England have vowed to keep Australia in a spin following Moeen Ali's match-winning turn at The Oval.
Moeen took two wickets for three runs in eight balls, securing England an early advantage that proved sufficient for their three-wicket win in London.
England made heavy weather of picking off their paltry 215 victory target, but crept over the line for an immediate advantage in the five-match series.
And now captain Eoin Morgan has admitted he will keep looking to Moeen and Adil Rashid to turn the screw on Australia's spin struggles.
"We used a lot of spin in the winter against Australia in Australia," said Morgan.
"Different scenarios might change things. But when the guys are bowling as well as they have today, I think more than likely we'll probably go with that balance.
"Certainly with the left-handers that Australia have, Moeen is an option to go to early.
"He can be a real threat and doesn't mind bowling in the power play. It created an opportunity for us today.
"With the bat we were below par but managed to get over the line.
"It's a big positive to take because it's a characteristic that we're going to need.
"The most important thing is that we did get the win.
"Before the Scotland game I mentioned how going into the World Cup and trying to replicate tournament-based cricket is getting wins when you don't have a great day. Finding ways to get over the line is important, and today we did a really good job of it."
Morgan's 69, Joe Root with 50 and Moeen with 17 will all feel they should have finished the game for England themselves.
Instead it was left to David Willey to hit his best England score of 35 not out, sealing the win with a big six.
Moeen admitted England must now target the series victory, with the second clash looming large in Cardiff on Saturday.
"I feel quite good with the ball, and I'm trying to adapt to the wicket, in terms of pace and things like that," said Moeen.
"We managed to get them three down and you can afford to bowl a bit slower and spin it more in situations like that.
"It's always nice to perform for England and to win games. The most important thing was that we managed to win today.
"Hopefully we can take some confidence from here and go on to win the series as well."
Australia will be relieved to have returned to international cricket for the first time since March's ball-tampering scandal.
But new captain Tim Paine admitted the tourists can ill afford to keep posting such disappointing totals and remain competitive.
"We didn't get enough runs out of our top five and you don't win too many one day games when the highest score of your top five is 22 or 23 - it's pretty simple," said Paine.
"We've got enough batting to score more than 214."
Asked if Australia's top concern remains their handling of spin, Paine continued: "Today it was, no doubt about that.
"It's something the whole group's been working on, something we speak a lot about trying to improve.
"It's a work in progress, we haven't been fantastic at it, but we've trained really hard at it.
"It's just up to our guys to be able to translate what they are working on in the nets out into the game. That's a little bit more difficult than it may seem under pressure."