Sydney created most of the chances in a game attended by just 4039 spectators, but struggled to get shots on target, especially kicking into the strong breeze in the second half.
Visiting goalkeeper Oh Seong-Hoon saved strong efforts from Adam Le Fondre early in the game and from Anthony Caceres just after halftime, but had trouble reaching the halfway line with his second half goal kicks into the wind..
Englishman Le Fondre was at the heart of most of Sydney's best first half moments, as the home team made the running.
He had a fourth minute shot blocked by the goalkeeper and had another header and shot off target and also set up chances for Milos Ninkovic and Reza Ghoochannejhad.
In the first half, Ulsan weren't content just to defend.
Brazilian striker Junior Negrao had a header saved by Andrew Redmayne and was off target with another attempt, while American international Mix Diskerud hit a weak shot straight at the keeper.
Chances were at a premium in the second half as Sydney struggled to produce penetrating and accurate crosses in the testing conditions and Ulsan sat back.
Caceres had a stinging shot palmed away and fellow midfielder Josh Brillante was off target with two attempts.
Sydney ended up wearing their away kit as the referee from Qatar decided on the eve of the game there was a clash between their home strip and Ulsan's away gear, which also has a sky blue element.
