Essex has reached 3-299 at stumps on day two against Australia, on a flat track in Chelmsford.
Australia were dismissed for 562 early on day two, with Mitch Marsh finishing with a top score of 169 off 188 balls.
The home side got off to a good start, with openers Westley and Mickleburgh sharing a 78 run stand before Mickleburgh was clean bowled by Starc by for 29.
However, that was only the start, with Westley and Bopara combining for a brilliant 213-run second wicket stand.
Westley was eventually dismissed for 114, after hitting 24 fours and one six in an attacking and free flowing innings. He was particularly aggressive towards Nathan Lyon, with the off-spinner conceding 54 runs in his first five overs.
Next batsman in, Jamie Porter, was then bowled for a duck by Mitchell Starc after facing just three balls.
Bopara remains unbeaten on 86 overnight, while Browne is yet to face a ball, with Essex in a strong position at 3-299.
See the full scorecard at Cricket.com.au