The left-arm paceman finished with a career-best 6-31 in his 100th one-dayer as Australia restricted Sri Lanka to 191 before racing to a seven-wicket win on Wednesday night for a 1-0 lead in the five-match series.

"You know it's always going to be a challenge in these conditions. It's always hot, the wickets are always pretty flat and slow," Johnson, 29, said after the day-night match.

"You get yourself up for these challenges. I felt pretty calm. It was my hundredth game which was pretty exciting."

Johnson's figures were the fourth-best by an Australian in one-dayers after Glenn McGrath (7-15), Andy Bichel (7-20) and Gary Gilmour (6-14).

"It's exciting to be ranked against those guys," said Johnson, who was surprisingly pressed into the attack as the sixth bowler on Wednesday.

"But that was what was needed at the time. Sri Lanka got off to a very good start with the new ball and the spinners came on and slowed things up a bit. It gave me an opportunity to use my skills."

Johnson struck in his first over when he removed Mahela Jayawardene before having Kumar Sangakkara caught in the covers off a slower ball. He also dismissed Angelo Mathews and Jeevan Mendis in his opening seven-over spell.

Australian captain Michael Clarke was delighted at his fast bowler's performance. "He bowled beautifully," said Clarke.

The remainder of the tour features three Tests after the one-day series.

"I'm happy with our performance, but we've still got a long way to go and I hope that (this) is just the start of what's to come," said Clarke, who hit an unbeaten 53 alongside half-centuries from Shane Watson and Ricky Ponting.

"We showed we are a very good one-day team and we can adjust to different conditions. I just hope we can continue to play like this."

The second one-dayer will be played in the southern town of Hambantota on Sunday.

Copyright AFP (Agence France-Presse), 2011