Inigo Calderon's first home game in charge as Bristol Rovers manager ended in disappointment as in-form Leyton Orient ran out winners at the Memorial Stadium.
It left Rovers hovering just above the League One relegation zone while the O's are closing in on the play-off zone following a ninth game without defeat.
Manchester United academy product Ethan Galbraith put the visitors in command on nine minutes when the right-back's low 22-yard drive beat Josh Griffiths' dive and went in off his right-hand post.
Rovers were handed a lifeline when Dan Happe felled winger Luke Thomas in the penalty box and veteran striker Chris Martin, on for the injured Promise Omochere, coolly converted his spot-kick, sending Josh Keeley the wrong way on 32 minutes.
Richie Wellens' side regained the lead on 39 minutes in controversial circumstances when Tottenham loanee Jamie Donley curled in a stunning free-kick after Ruel Sotiriou was harshly adjudged to have fouled Sonny Perkins.
Substitute Charlie Kelman doubled the visitors' lead with his 10th goal this term on 53 minutes when the QPR loanee poked home a ball from Perkins after left-back Lino Sousa was dispossessed.
Martin gave Rovers hope on when he slotted Shaq Forde's home on 74 minutes, setting up a tense finale that saw the hosts denied an equaliser late on when Gatlin O'Donkor was penalised for handball
Report supplied by PA Media.
Bristol Rovers manager Inigo Calderon speaks to BBC Radio Bristol following defeat by Leyton Orient
