It was an open, attacking game from the opening minutes with Kevin Thomson's thirty-yard free-kick almost being spilled by home goalkeeper Giedrius Arlauskis in twelve minutes.
Fourteen minutes later Steven Naismith's header from a Sasa Papac cross
was held by the 'keeper.
Unirea soon responded - Vasile Maftei's thirty-yard dead-ball coming cannoning back off Allan McGregor in 28 minutes.
Sixty seconds later at the other end Kenny Miller's surging run ended with a low shot that was held by Arlauskis.
McGregor produced a superb one-handed save in 32 minutes to deny Iulian Apostol from a Serban Varga cutback.
Five minutes later Ricardo Vilana almost produced a stunning opener when from fully forty yards his effort was just inches too high.
Rangers ended the half on the attack - Kyle Lafferty curling the ball just wide from a Miller lay-off.
Unirea restarted on the offensive - Valeriu Bordeanu's 25-yard shot flashing wide of the target in 49 minutes,
Miller spurned a golden opportunity to break the deadlock on the hour when, playing a one-two with Steve Davis, his weak shot was held by Arlauskis.
Onofras twice threatened in 69 and 74 minutes respectively - a header from Sorin Frunza's cross being held by McGregor, who then pushed out an angled drive after the forward had beaten the offside trap.
McCulloch it was who opened the scoring in 78 minutes when his 25-yard shot from a Lafferty lay-off found the corner of the net.
It was the club's first-ever goal in Rumania - and suddenly the Ibrox men were back in the hunt for the knock-out stages.
Within seconds at the other end Wilson, who had played well throughout, headed off the line after Frunza had rounded McGregor.
Novo replaced Miller and John Fleck came on for Thomson as time ticked on.
Just when it appeared that Rangers had secured a vital win however a mistake by Novo allowed Onofras the opportunity to crash home a stunning equaliser from 25 yards in 88 minutes.
Even then, the visitors might have regained the lead in injury time when from Fleck's corner Papac sliced his shot wide.
The game ended all square - leaving one with the feeling that the last sixteen of the Champions League has slipped out of reach.
UNIREA URZICENI Arlauskis; Bordeanu, Galamaz, Maftel, Brandan; Balan (Onofras 27), Ricardo Vilana (Paduretu 80), Apostol, Varga (Semedo 80); Frunza, Bilasco
UNUSED SUBS Tudor, Mehmedovic, Paraschiv, Nicu
RANGERS McGregor; Whittaker, Weir, Wilson, Papac; Naismith, Davis, McCulloch, Thomson (Fleck 84), Lafferty; Miller (Novo 80)
UNUSED SUBS Rothen, Alexander, Boyd, Beasley, Smith
REFEREE Claus Bo Larsen (Denmark)