Jan Vennegoor of Hesselink's hat-trick in a demolition of St Mirren at Parkhead helped Celtic extend their lead at the top of the Bank of Scotland Premier League to 20 points.

The champions endured a nervy few moments just after the interval when Stephen McGinn equalised the Dutchman's first-half opener.

But in a second-half whirlwind, big striker Vennegoor of Hesselink grabbed another two goals, one from the spot, with Aiden McGeady and substitute Kenny Miller also adding their names to the scoresheet.

In a week where the adverse weather had been arguably the main talking point throughout the country, the forecast at Celtic Park for the visit of St Mirren was straightforward - heavy pressure from the home side with a liberal sprinkling of goals for the champions.

And by the end of the 90 minutes, that is exactly what the fans had witnessed.

Striker Craig Beattie squandered three good early chances to give the home side the lead.

He had an angled shot from 16 yards blocked by Saints goalkeeper Chris Smith and from the resultant corner, midfielder Thomas Gravesen's volley from the edge of the box was brilliantly parried by the Paisley number one.

When the ball rebounded to Beattie 10 yards out, he volleyed high over the bar with the goal gaping.

It was one-way traffic and in the ninth minute Beattie was again through on goal. He lobbed Smith at the edge of the Buddies penalty area but the ball ran wide.

It seemed only a matter of time before the breakthrough and it duly arrived in the 16th minute after Celtic forced another corner. When Shunsuke Nakamura's flighted ball from the left arrived in the six-yard box, Vennegoor of Hesselink rose among a throng of bodies to bullet in a header which gave Smith no chance.

Gordon Strachan's side appeared to ease off a little but in the 27th minute McGeady took a Beattie pass just outside the Paisley side's penalty area, turned inside and drove just wide of Smith's right-hand post.

Moments later a challenge by Smith at the feet of Beattie inside the Saints box brought shouts for a penalty from the home fans, but referee Craig Thomson was unimpressed.

The home side's dominance which characterised the run of play in the first half was reversed dramatically two minutes after the interval when the visitors grabbed a sensational equaliser.

Simon Lappin's cross brushed Mark Corcoran before landing at the feet of McGinn 20 yards from goal and, with the Parkhead defence in an apparent trance, the Saints midfielder reacted quickly to dispatch his shot into the net.

It was difficult to know who was more stunned, the small band of St Mirren fans or the players who enjoyed a lengthy celebration at the corner flag in front of them.

The goal changed the atmosphere inside Celtic Park, the home fans immediately changing from complacent to complaining.

But on the hour mark Celtic's lead was restored after Lappin conceded a penalty when he clumsily barged Nakamura in the back inside the St Mirren box.

Vennegoor of Hesselink stepped up to send Smith the wrong way for his ninth goal of the season. Those in green and white had their nerves calmed.

In the 69th minute the champions extended their lead when McGeady received a cross-cum-shot by Beattie at the far post and drove the ball back across Smith and into the far corner of the net.

McGeady was immediately replaced by Derek Riordan in a substitution that was waiting to take place before the Republic of Ireland player scored.

In the 75th minute Vennegoor of Hesselink completed his hat-trick when he took a Beattie pass 14 yards out, turned and drove past the hapless Smith.

And with nine minutes remaining Celtic substitute Kenny Miller, who had replaced Beattie, scored the home side's fifth from just a few yards out after Smith had blocked a drive from Riordan.

Teams

Celtic Boruc, Telfer, Pressley, O'Dea, Naylor, Nakamura,Gravesen, Jarosik (Sno 61), McGeady (Riordan 70),Vennegoor of Hesselink, Beattie (Miller 78).

Subs Not Used: Brown, Zurawski, Conroy, Cuthbert.

Goals: Vennegoor of Hesselink 16, 61 pen, McGeady 69,

Vennegoor of Hesselink 75, Miller 82.

St Mirren Smith, van Zanten, Millen, Maxwell, Broadfoot,Brady, McGinn (Sutton 71), Brittain, Lappin (Gemmill 82), Reid,Corcoran (Kean 77).

Subs Not Used: Hinchcliffe, McGowne, Potter, McKenna.

Booked: Lappin.

Goals: McGinn 47.

Att: 58,382

Ref: C Thomson (Scotland).