Alex McLeish's side had gone seven games without a victory on their travels but a trip to the Reebok Stadium was the perfect tonic to that miserable run.
Bolton have now lost 12 of their last 15 league matches -- and seven of eight at home -- and this result, combined with Wigan's victory at West Brom, left Owen Coyle's strugglers languishing in 20th place.
They fell behind when Albrighton prodded in Gabriel Agbonlahor's cross midway through the first half and Petrov added to the second soon after.
Ivan Klasnic reduced the deficit 10 minutes into the second half, but the hosts could not salvage a point and were booed off by their angry fans.
After respects had been paid around the ground to former Bolton midfielder Gary Speed with a minute's applause, it was the hosts who created the first real chance of the game when Chris Eagles swung a free-kick towards the box and Gary Cahill headed into Brad Guzan's arms.
A slip from Cahill allowed Charles N'Zogbia to cross to Petrov, who was right in front of goal but put his shot wide.
Darren Bent also failed to convert when he really should have scored, the unmarked Villa striker seeing his effort come back off the legs of Jussi Jaaskelainen.
Wanderers were struggling to contain their opponents' attacking play and it came as little surprise when Villa made the breakthrough just after the half-hour mark, Albrighton on hand to tap in Agbonlahor's delivery from the left.
Within six minutes, the visitors had doubled their lead, Petrov's drive taking a deflection off Cahill on its way in.
Bolton might have pulled one back two minutes before the break, but Guzan did well to block Kevin Davies' header.
The hosts showed more purpose at the start of the second half and after Guzan had dived to push away a curler from Eagles, Wanderers got one back in the 55th minute.
Klasnic showed his predatory instincts, sweeping in his seventh goal of the season after Zat Knight's shot had caused a scramble in the box, but Bolton were unable to maintain their momentum as Villa held on to win.
Source: AFP
Source: AFP