THERE are some who cannot even bear the thought of Bolton Wanderers doing Manchester United a favour, but Sam Allardyce and his Mean Machine are in the mood and the form to do some serious damage to Arsenal's title challenge.

The irony would not be lost on Sir Alex Ferguson but there is now the distinct possibility that, having denied the Old Trafford Reds five points this season, Wanderers could hand them the championship crown on a plate on Saturday afternoon - and secure their own Premiership future into the bargain.

Arsene Wenger's Gunners will take some stopping, of course, but they will do well to break down a defence that has conceded just one goal in 540 minutes of high tension football.

Five clean sheets in six games has taken Big Sam and his survival squad to the brink of securing a third top flight term and they are showing no signs of cracking under the pressure.

In fact they are getting meaner by the hour, judging by the manager's readiness to voice his delight at how his spoiling tactics in Monday's Ewood Park derby goaless draw took them a point nearer his safety target.

He has revelled in seeing his team play attractive, entertaining football with the likes of Jay-Jay Okocha and Youri Djorkaeff strutting their stuff but he has never lost sight of his ultimate objective - to get to 41 points as quickly as possible and by whatever means. And with West Ham, Birmingham , Fulham and the rest still going strong, he makes no excuses.

"I can't remember a local derby being pretty," he responded at the suggestion that Wanderers would get no style marks for this display.

"It was more important we spoiled the game and stopped Blackburn playing their football, which we did."

He did not mind admitting either that Wanderers rode their luck when Andy Cole embarrassingly missed what Graeme Souness described as a "bread and butter" chance in the first half and when Damien Duff somehow got the ball and his feet in a tangle when he had a tap-in for the winner, right at the death.

But, in the main, they frustrated Rovers with sound, determined defending and on the one occasion when the back line was breached, Jussi Jaaskelainen confirmed his impressive run of form with an outstanding save to double Cole's misery.

"He was there when we needed him," Allardyce said of the big Finland keeper Kevin Keegan is reported to be lining up as Peter Schmeichel's successor at Manchester City. "That's what we've been asking him to do all season and it's brought us a crucial point."

Souness applauded Wanderers for being resolute but showed his frustration when he spoke of two points dropped. "We've done everything but put the ball in the back of the net," the Rovers boss suggested. "I can't remember a Brad Friedel save and can't remember them worrying us.

"Give them credit because they've worked hard but on another day, if we play like that, we are going to win the game."

With West Ham bouncing back from Saturday's Reebok defeat to beat Middlesbrough, Wanderers saw their lead cut from six points to four but they were in buoyant mood as they made the short trip home. With only three games to play, the Hammers have it all to do.

"We knew West Ham were going to beat Middlesbrough," Per Frandsen said after a non-stop performance. "So it was a very important point for us.

"We are definitely in the best position now. We've been confident all the time but now we aren't giving goals away and I think we can give Arsenal a very good game.

"It will be difficult but we are confident of playing well at home - we've won the last three games - and we always seem to play well against the top teams."

The confidence might have been dented if Rovers had the finishing power to match the pace and penetration of the dashing Duff, who was a constant threat.

But Bruno N'Gotty stuck to his task well and with the Gudni Bergsson-Florent Laville partnership as solid as ever, Jaaskelainen was

tested but rarely stretched, although Garry Flitcroft and Hakan Sukur should have done better with Cole-created chances.

Wanderers did little to suggest they might win it but an Ivan Campo header and a Jay-Jay Okocha free-kick gave their supporters at the Darwen End the encouragement of knowing that, at 0-0, there is always hope.

They might even have snatched it if Friedel had not covered his near post to block Bernard Mendy's angled shot after Pierre-Yves Andre's cross flashed across the face of the Rovers goal but they were happy with what they got.

Allardyce did the sums and reckoned: "One goal conceded in six games suggests we are not going to lose our next three. And that should be good enough."