Most title chases turn on a pivotal match but Scotland's tend to explode. Rangers and Celtic meet for the sixth time this season at Ibrox tomorrow with the Premier league effectively to be settled in the frenzy.

"I hear all this stuff about if it is a draw it is still wide open but in my gut I don't believe it," offered Barry Ferguson of Rangers. "In the pit of my stomach I feel we have to win it. Simple as that."

Reality suggests as much.

Rangers, apparently a team in transition, welcome their rivals, who lead by two points with five matches to play. Given the Old Firm sit 25 points clear of third-placed Hibernian, it is safe to assume neither would anticipate dropping a point in their remaining four matches against the also-rans, leaving tomorrow's fiercely anticipated derby as the be all and end all to the season.

That it has even come to this represents something of a triumph for Alex McLeish. The Rangers manager appeared to be wilting in the glare of Martin O'Neill's successes across Glasgow earlier this season, his position threatened by a financially devastating aggregate defeat by CSKA Moscow in qualification for the Champions League and undermined by an early defeat at Parkhead.

The 1-0 defeat back in August, inspired by the recently signed Juninho, was Rangers' seventh successive reverse against O'Neill's side, a sequence stretching back to March 2003.

Yet, for all that Celtic have edged as far as eight points clear at times this term, durability has kept Rangers at their shoulder. They eliminated each other from Scotland's cup competitions - Rangers winning the League Cup tie, Celtic the FA Cup rematch - but McLeish's side have won their last two league meetings, plucking timely victories from furious occasions. In November they trailed their visitors by four points before winning 2-0; Rangers' first league success at Parkhead in five years, pre-dating the O'Neill era, ate into a similar advantage back in February.

The clash at Ibrox tomorrow will be the most significant yet, despite attempts to dead-bat its importance. "To lose and be five points behind with four to play would make it very difficult for us, but a title decider? Not in my eyes," said McLeish.

"If we were to win, it would put us a point clear with an awful lot of points left to be won and lost. It's about having the destiny of the championship back in our hands. Victory would give us a psychological edge but this is no time to get carried away."

Such caution is not misplaced. So resurgent were Rangers at the turn of the year - they notched eight successive wins from mid-January to early March - they would have edged clear at the top had five points not been tossed away in their past two home games against Inverness Caledonian Thistle and Dundee United. Neither club made the top half of the table after the recent cut-off.

Upheaval has hindered their progress. The huge turnover in players has disrupted rhythm - Alex Rae, Nacho Novo, Thomas Buffel, Jean-Alain Boumsong, Dado Prso, Sotiros Kyrgiakos, Gregory Vignal and Ferguson have all arrived, with Boumsong sold on already and other key personnel, from Mikel Arteta to Craig Moore, also making way.

"People say Celtic have dropped off a bit while we have improved slightly," says McLeish. "Maybe there is an argument there but they're still a well established, mature side and that'll make it so hard for us on Sunday. But we've come within reach of the championship. Now there's an opportunity there that perhaps I didn't expect."

In the din at Ibrox tomorrow expectations will soar.