PERTH, October 17, 2013 (AFP) - Australian duo Clint Rice and James Nitties led after the opening round at four-under 68, along with South Korean Jin Jeong and Sweden's Peter Hedblom.
World number 21 Johnson shot a three-under 69 with van Pelt one stroke further adrift.
England's 12-time European Tour winner Paul Casey (four-over) and rising South African star Branden Grace (one-over) had days to forget.
Australians Nick O'Hern, Brady Watt, Nick Cullen and Dimitrios Papadatos were among a large group of players at three-under.
The Perth International, Australia's richest tour event, is the nation's only tournament to be co-sanctioned by the European Tour and the PGA Tour of Australasia this season.
Johnson, who was forced to cancel a media conference on Tuesday due to a cold, said he was feeling better.
"I'm fine. I'm feeling way better than I was," Johnson, 29, said. "I've just got a little bit of a cough which is OK. I'm back to where I feel good enough to play good golf."
The American said he was satisfied with his round, which included five birdies and three bogeys.
Defending champion Van Pelt won at Lake Karrinyup last year after a battle with countryman Jason Dufner.
Jin, who moved from South Korea to Australia seven years ago when he was just 16, produced the highlight of the day when he holed a 167-yard shot on the par-fourth 18th for eagle.
"I didn't think it was going to go in," Jin said. "I thought it would be another three or five feet. But people started clapping and yelling, so yeah, quite happy."
Leading scores after the opening round of the $2 million EPGA-sanctioned Perth International at Lake Karrinyup (par-72) in Perth on Thursday (Australia unless stated):
68 - Peter Hedblom (SWE), Jin Jeong (KOR), James Nitties, Clint Rice.
69 - Sam Little (ENG), Dustin Johnson (USA), Nick O'Hern, Brady Watt, Nick Cullen, Dimitrios Papadatos, Bjorn Akesson (SWE), Fredrik Andersson Hed (SWE).
70 - Bo Van Pelt (USA), Rohan Blizard, Anthony Brown, Mark Brown (NZL), JB Hansen (DEN), Robert Coles (ENG), Josh Younger, Thomas Petersson (SWE).
71 - Brett Rumford, Tom Bond, Christopher Campbell, Ross McGowan (ENG), Brett Rankin, Soren Hansen (DEN), David Bransdon, Espen Kofstad (NOR), Joel Sjoholm (SWE).
72 - Ryan Haller, Peter Cooke, Danny Willett (ENG), Richard Finch (ENG), Peter Wilson, David Drysdale (SCO), Ashley Hall, Simon Wakefield (ENG), Neven Basic, Craig Parry, Brody Ninyette, Bradley Lamb, Adam Bland, Paul Spargo, Marcus Fraser, Ross Fisher (ENG), Oliver Fisher (ENG), Daniel Popovic, Chris Doak (SCO).
Selected scores
73 - James Morrison (ENG), Michael Hoey (NIR), Craig Lee (SCO), Jose Manuel Lara (ESP), Johan Edfors (SWE), Anthony Snobeck (FRA), Michael Jonzon (SWE), Branden Grace (RSA), Peter Lawrie (IRL), Gregory Havret (FRA), David Higgins (IRL), Mikko Korhonen (FIN).
74 - Gary Lockerbie (ENG), Alexandre Kaleka (FRA), James Kingston (RSA), Alexander Levy (FRA), Scott Henry (SCO)
75 - Fabrizio Zanotti (PAR), Peter Erofejeff (FIN), Oscar Floren (SWE), Richard Bland (ENG), Mark Tullo (CHI), Tjaart Van Der Walt (RSA)
76 - Soren Kjeldsen (DEN), Paul Casey (ENG), Justin Walters (RSA), Richard McEvoy (ENG), Rikard Karlberg (SWE).
77 - Andreas Harto (DEN), Lasse Jensen (DEN), Brandon Stone (RSA), Chris Paisley (ENG).
78 - Matteo Delpodio (ITA), Lorenzo Gagli (ITA), Dawie Van Der Walt (RSA)
79 - Matthew Nixon (ENG)
81 - Joakim Lagergren (SWE)