The world number 11 and current New Zealand Amateur Champion, consolidated his opening round of 7-under-par, 65, at Mount Lawley Golf Club, with a second round 70 at Lake Karrinyup Country Club to be at 9-under-par and a two stroke margin over his nearest rivals, Jordan Sherratt and Ryan Woodward.
Sherratt and Woodward are at 7-under-par after Sherratt fired an impressive second round 5-under-par, 67, at the difficult Lake Karrinyup Country Club. Woodward's rounds of 68-69 has ensured the emerging Victorian junior remains competitive in these championships.
These championships are important to Jager in more than one respect.
Not only is Jager seeking to claim his first Australian national title, he's also keen to advance his world ranking. Jager recently slipped back outside the world's top-10 and knows of the importance of being inside that number before returning to contest the main US amateur events in June.
The second round mover in Perth was Ryan Fox with an impressive 6-under-par, 66, at Lake Karrinyup to move the New Zealander into 4th position for the championship at 5-under, two behind Sherratt and Woodward. Luke Bleumink is at 3-under after rounds of 73-68, to be in outright 5th position.
Bryden Macpherson, the current Australian Amateur Stroke champion, started the second round only a stroke behind Jager but a 4-over-par 76, around Lake Karrinyup has the US based collegiate player at 2-under-par in a pack of four others, including Jin Jeong, Brady Watt, Chien-Yao Hung and Cameron Fabian.
The 36-hole cut was at 6-over-par with Brendan Smith and Jason Scrivener missing the mark narrowly by a two strokes. For them this championship would be an obvious disappointment after both showed promise in earlier events this year.
The leading 32 players following Sunday's 4th round qualify for elimination match play starting Monday at Lake Karrinyup to determine the Australian Amateur Champion at Wednesday's final.