Promotion hopefuls Bolton saw their four-match winning run end as Dan Agyei netted the only goal of the game to give Leyton Orient a 1-0 victory.
Agyei scored in the 54th minute when he seized on a through-ball from Jayden Sweeney and slipped the ball past goalkeeper Nathan Baxter for his third goal in as many Sky Bet League One games.
However, Orient boss Richie Wellens was dismissed by referee Alex Chilowicz in the 81st minute after preventing a Bolton player from taking a quick throw-in. Bolton assistant manager Pete Atherton was shown a yellow card for his part in the altercation.
The visitors’ leading scorer Dion Charles squandered the best two chances for his side, including a header from a George Thomason cross that struck the upright when he found himself unmarked at the far post.
After a closely-contested first-half, Orient were rewarded for their sustained spell of pressure after the interval with the strike from Agyei.
Their watertight defence, which has now played five successive matches without conceding a goal, remained resilient as the hosts held on for a win which sees them climb to ninth in the table.
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