John Hartson struck the 30-goal mark with a second-half double to take defending champions Celtic back to the top of the Bank of Scotland Premier League.

Rangers once again tested the nerves of their Glasgow rivals by beating Hearts at Ibrox 24 hours earlier to return to the summit.

But after a tense first half, Wales star Hartson pounced twice in the second 45 minutes of Celtic's final home game of the season.

The outcome means Celtic climb back above Rangers and take a two-point lead into the last two rounds of SPL matches, while Aberdeen's loss meant there was cause to celebrate for Hibernian who are now within a point of guaranteeing third place and a UEFA Cup slot.

The Celtic supporters were pumped up after a heartfelt plea from manager Martin O'Neill this week for more encouragement.

O'Neill brought back Robert Douglas, Didier Agathe, Chris Sutton and Ulrik Laursen after injuries, and out went David Marshall, Joos Valgaeren, Aiden McGeady and Shaun Maloney from the team which slumped to a shock home defeat to Hibernian last week.

Aberdeen looked a threat on the break in the early stages, before Hartson missed a gilt-edged opportunity to give the champions the lead in the 19th minute which would have eased the tension.

Darren Mackie under-hit his back-pass to Andrew Considine and Agathe nipped in to take the ball and find Sutton in the area.

The Englishman pulled the ball back from the byline to Hartson but Zander Diamond threw his leg out to block his right-footed shot from seven yards.

The visitors would have snatched the lead on the half-hour mark had it not been for the heroics of Jackie McNamara.

Richie Byrne got on the end of Scott Muirhead's corner and looked destined to spark wild celebrations in the blue half of Glasgow, but Celtic skipper McNamara was in the right place at the right time to head off the line. Diamond blazed the loose ball over the top.

Celtic felt they should have had a penalty when Alan Thompson was pulled back by Hart, after collecting Petrov's through-ball.

But referee John Underhill looked long and hard before deciding there was was no offence, much to the annoyance of the home crowd.

The home crowd shouted for another spot kick in the 43rd minute when Bulgarian Petrov went down under the strong challenge of Anderson.

However Celtic breathed a sigh of relief before the break when Mackie got behind their defence and pulled the ball across the face of goal where Thompson was on hand to make a vital block.

O'Neill was forced to make a change at the break and he bravely chose to bring on Craig Beattie in place of Laursen as the Hoops went to three at the back.

That changed the game and the champions broke the deadlock just two minutes into the second period.

Hartson did not get the best of connections to Thompson's free-kick, but he did enough to send the ball spinning past Esson and towards the back of the net.

Despite Considine's best efforts, the Aberdeen man could only blast the ball into the roof of the net.

Petrov attempted to kill the game off moments later with a long-range blast but the Aberdeen goalkeeper pushed his effort away.

Celtic still looked nervous at the back and Muirhead might have silenced the crowd in the 53rd minute, after being teed up by Chris Clark just seven yards from goal, but his first touch was poor and the ball ran away.

Hartson came close to doubling his and Celtic's tally for the afternoon in the 58th minute as he rose to get on the end of Thompson's cross, but the ball bounced just wide of the far post with Esson well beaten for the second time.

The Aberdeen 'keeper had no such problem with a rare Neil Lennon strike from the edge of the box, but he was in debt to Considine in the 63rd minute.

Hartson nodded Thompson's cross into the danger area where Beattie pounced to send the ball goalwards, and the Aberdeen defender got back to clear off the line.

Aberdeen's hopes of a famous result were dealt a blow when Kevin McNaughton was helped off in the 65th minute and replaced by Lubomir Blaha. Considine made way for Gary Dempsey moments later.

But Hartson, the Scottish player of the season, alleviated the anxiety when he converted Sutton's cross from five yards with 19 minutes remaining for his 30th goal of the season - the target he had set himself at the start of the campaign.

Beattie could have added to Celtic's advantage in the 80th minute but he guided his header straight into the arms of Esson after more good work by Sutton.

Hartson might have clinched his hat-trick in injury time as he fired over from Beattie's centre - but his work had already been done.

Teams

Celtic Douglas, McNamara, Varga, Balde, Laursen (Beattie 45), Agathe, Petrov, Lennon, Thompson, Hartson, Sutton.

Subs Not Used: Marshall, Valgaeren, Lambert, Maloney, Wallace, McGeady.

Goals: Hartson 47, 71.

Aberdeen Esson, McNaughton (Blaha 65), Diamond, Anderson, Severin, Hart, Considine (Dempsey 67), Mackie, Byrne (Winter 83), Muirhead, Clark.

Subs Not Used: Preece, Adams, Foster, Macauley.

Att: 59,498

Ref: J Underhill (Scotland).