Constantin Budescu scored twice to dump West Ham out of the UEFA Europa League in the third qualifying round as Astra secured a 2-1 second-leg victory on Thursday.
The Romanian outfit held the away-goal advantage following a 2-2 draw in the first leg at Upton Park, but a weakened West Ham XI swung the tie in their favour when Manuel Lanzini found the bottom left-hand corner just three minutes into his competitive debut for the Premier League club.
However, Astra managed to establish a foothold in the match and Budescu hit the right-hand upright from a set-piece in the 15th minute before restoring parity on the night with a driven effort.
One goal became two inside three minutes for Budescu as he coolly slotted home from the centre of the penalty area, leaving West Ham needing a goal to force extra time.
But that crucial strike was not forthcoming for the London side, who are left to focus on their domestic campaign after losing 4-3 on aggregate.
Despite heading to Romania on the back foot, Slaven Bilic – with one eye on Sunday's Premier League opener against Arsenal - picked a relatively inexperienced XI to keep alive his side's Europa League hopes, with Kyle Knoyle and Doneil Henry joining Lanzini in making their competitive bows for the club.
And the approach looked to be paying off when Lanzini – a loan signing from Al Jazira - cut in from the left to drill a low right-footed effort just inside the post after three minutes, with the home defence caught cold.
Astra came agonisingly close to equalising in the 15th minute, when an audacious Budescu free-kick from a difficult angle dipped over the head of goalkeeper Darren Randolph and struck the right-hand upright.
The hosts were beginning to settle and pulled level on the night through Budescu in the 33rd minute – the attacker sending the ball swerving out of the reach of Randolph after shooting between the legs of debutant Henry on the edge of the box.
West Ham's task became even bigger three minutes later, when Budescu found himself in acres of space on the penalty spot and, with plenty of time to pick his shot, made no mistake in finding the net.
The visitors minimised the Astra threat after the interval but struggled to carve out clear-cut opportunities of their own, limited to half-chances and optimistic shots from long range.
Denis Alibec tested Randolph as the match entered the last 10 minutes, with West Ham unable to pose a similar threat at the other end.
Alibec almost added a third goal late on when his effort from a tight angle hit the outside of the post, but that miss did not prove to be costly as the Premier League side bowed out with a whimper.
