Goalkeeper Neil Alexander was the hero as Rangers booked their place in the Scottish Cup final following a tense penalty-shoot out against a battling St Johnstone side.

Alexander - between the sticks for the injured Allan McGregor - saved spot-kicks from both Steven Milne and Jody Morris following a 1-1 draw.

Nacho Novo had cancelled out Daniel McBreen's opener in extra-time.

Rangers will now face another First Division side - Queen of the South - here at Hampden in the showcase on May 24.

Only Christian Dailly, Steven Whittaker and Carlos Cuellar - captain for the day in the absence of Barry Ferguson - survived from the defeat at Celtic Park midweek, as Rangers made eight changes.

Some of those were enforced with McGregor and Lee McCulloch sustaining injury on Wednesday night and David Weir suspended for his part in a fracas at the end of the Old Firm derby.

With the pursuit of four trophies this season finally beginning to take its toll, the last thing Rangers needed was the loss of two players in the opening 20 minutes at Hampden.

Chris Burke was first leave the pitch on a stretcher after just eight minutes after being caught in the ankle by a crunching challenge from Kevin Rutkiewicz.

The winger was replaced by Thomas Buffel, the Belgian making his first appearance since the 6-0 win over East Stirling in the Scottish Cup back in January.

There was further concern when Steven Naismith limped off the park after being stamped on by Martin Hardie.

He was able to return to the action but, like Burke, left on a stretcher seconds later after appearing to damage his knee and was replaced by Steven Davis with 20 minutes gone.

Rangers attempted to recover from the losses in personnel by cranking up the pressure and Kevin Thomson embarked on an impressive run past two Saints players before firing wide when a delicate chip would have been a better option.

Buffel then produced a decent finish to leave the net bulging from six yards but the nearside assistant had correctly flagged for offside before the shot had left his boot.

Novo passed up the best chance of the first half when he pounced on a dreadful pass back from Goran Stanic only for his shot to clip the body of veteran goalkeeper Alan Main and trundle wide of the far post.

Stanic went some way to redeeming himself moments later when he intercepted a lovely flick from Davis from the left, with Daniel Cousin loitering with intent in front of goal and waiting for a simple finish from a few yards.

Reports at half-time claimed Burke and Naismith were still in the national stadium and had not been taken to hospital, suggesting their injuries may not be as serious as first feared.

The second half was just a minute old when Main was called into action. Novo threw himself in front of a Whittaker cross from the right flank only to look on in disbelief as the 40-year-old tipped the header just over.

At the other end, St Johnstone offered up their best chance so far. Hardie's nod-down fell to the feet of Milne, who unleashed a powerful shot from 18 yards that would have been unstoppable had it been on target.

Milne - whose double sent Rangers crashing out of the CIS Insurance Cup in November 2006 - then rose above Dailly to reach a Liam Craig ball only for his header to flash across goal and wide.

Rangers could have all but killed off this turgid tie with 10 minutes to go when Whittaker raced onto a Davis ball but was denied by Main, who pounced off his line to produce a timely block before the full-back could pull the trigger.

Rangers threw everything at their First Division challengers.

Novo collected a long ball from Alexander and flicked into the path of Cousin but Main was first to the ball, before Davis saw a close-range header hooked off the line by Craig as the tie went into extra-time.

Substitute McBreen finally broke the deadlock with 94 minutes on the clock. Paul Sheerin provided a teasing cross from the left and McBreen connected in plenty of space to dispatch a downward header past Alexander.

Rangers were back on level terms eight minutes later when Cousin was tripped in the box by Gary Irvine and referee Dougie McDonald immediately pointed to the spot.

Novo did the honours from 12 yards and finally breached Main's goal with a finely struck penalty which nestled in the keeper's right-hand corner.

The epic last four clash was eventually decided by a shoot-out, with Alexander saving a penalty from Milne, and Main denying Brahim Hemdani, before the Rangers keeper blocked from Morris to finally secure a place in the Scottish Cup final.

Teams:

St Johnstone Main, Irvine, Rutkiewicz, McManus,Stanic (Anderson 91), Milne, Morris, Hardie (Sheerin 70),Craig, Jackson, MacDonald (McBreen 80).

Subs Not Used: Cuthbert, James.

Goals: McBreen 94.

Rangers Alexander, Whittaker, Cuellar, Dailly,Steven Smith (Broadfoot 90), Burke (Buffel 11), Hemdani,Thomson, Naismith (Davis 19), Novo, Cousin.

Subs Not Used: Graeme Smith, McMillan.

Booked: Dailly.

Goals: Novo 103 pen.

Rangers win 4-3 on penalties

Att: 26,180

Ref: D McDonald (Scotland).