Theo Robinson scored twice to help Colchester to a 3-0 win over his former club Swindon at the County Ground.
Tom Eastman was also on target as the U's ended high-flying Swindon's three-match winning streak.
Swindon dictated play in the first half but failed to properly test Colchester goalkeeper Dean Gerken, with Eoin Doyle's rifled shot wide being their best chance.
Colchester opened the scoring against the run of play when Eastman headed in a Cohen Bramall corner during first-half stoppage time.
Robinson made it 2-0 from Brendan Sarpong-Wiredu's cross, but Colchester had home goalkeeper Luke McCormick to thank by letting the ball squirm through him.
It was all over when Robinson made it 3-0 in the 75th minute with a powerful effort into the top corner after Frank Nouble led a quick break away.
The win moves Colchester up to 13th in the League Two table.