LUCKLESS Villa are beginning to resemble a diligently cultivated business which Is suddenly ruined by a stock market crash. Jo Venglos's careful Investors suffered their second Capital City collapse in a week at Loftus Road last night, just when their endeavours promised to yield a rich dividend. Against champions-elect Arsenal eight days ago, the surrender of three goals in six minutes proved the difference between respectability and humiliation in an anticipated defeat. The slump against Don Howe's rampant Rangers was not quite so spectacular, but the effect was considerably more dramatic. Substitute Brad Allen and defender Andy Tilson plundered two goals in the space of three minutes to transform Villa's potential profit-making situation into an all-too-familiar deficit. The likelihood is that there is too much in reserve for the team to go under (down to Division Two, that is), but this was a wasted opportunity to consolidate top flight security. A third League away victory appeared to have been safely deposited, courtesy of David Platt's 22nd goal of the season. The England midfielder made a powerful run from the half-way line before unleashing an explosive 20-yard drive described by Howe as "a goal in a million" after 33 minutes. By the hour, in fact, the visitors held a strong controlling interest in an entertaining contest, displaying resilience at the back, authority in midfield and the occasional threat of building on their advantage But the course of the game was turned by Howe's bold double substitution in the 71st minute, with Allen and England star Paul Parker plunged into the action to save Rangers' 10 match unbeaten run. Barely five minutes had elapsed when Allen turned the otherwise impeccable Paul McGrath to curl a shot beyond Lee Butler. Then Parker's cross enabled Tilson to head the winner after Villa had only half cleared a corner.