Celtic scored twice in stoppage time as they left it late to secure a 3-1 win over Aberdeen at Parkhead on Saturday.
Kris Commons had capitalised on a poor punch out by Dons keeper Jamie Langfield to fire Celtic into a 35th minute lead.
However, Aberdeen grabbed an equaliser in first half stoppage time as former Hoops player Niall McGinn finished off a well-worked move from a corner.
Langfield made amends for his earlier error as he made fingertip saves to deny Joe Ledley and Commons while Georgios Samaras hit the post.
McGinn came close to putting Aberdeen in front late on as he struck the post with a fierce strike before substitute Boerrigter scrambled home his first Celtic goal a minute into stoppage time.
Commons then secured the win with a tap-in in the third minute of stoppage time to keep Celtic five clear at the top and give his side a boost ahead of Tuesday's must-win Champions League clash with AC Milan.
The hosts had started in determined fashion but Langfield was well-placed to deal with a fierce Samaras strike from long range before he collected a weak header from Scott Brown.
However, the Dons keeper was at fault for Celtic's 35th minute opener. Langfield came off his line to punch clear an Izaguirre cross but the ball only went as far as the edge of the box where Commons was on hand to fire the ball past the stranded keeper for his fourth goal in his past five games against Aberdeen.
The lead was short-lived as Aberdeen grabbed an equaliser in first half stoppage time. Hayes headed on a corner and Zola's flick deceived Forster allowing McGinn to nip in and bundle the ball home from close range.
Celtic bombarded the Aberdeen goal at the start of the second half and only a fingertip save from Langfield kept out a superb 25-yard strike from Ledley.
Teemu Pukki was having a torrid time in front of goal for the Hoops and when Virgil van Dijk expertly teed him up for a shot at the edge of the box the Finnish striker sliced his effort well wide of the target.
The Hoops should have restored their lead on the hour mark when Samaras showed good skill to control a pass just outside the box before stabbing his effort past Langfield but the ball struck the base of the post.
Commons was next to come close when he raced clear down the inside left channel but Langfield got enough on his strike from a tight angle to turn it round the post.
Aberdeen were soaking up the pressure but should have done better in a rare chance at the other end when Joe Shauhnessy was allowed time and space in the box but the defender headed substitute Greg Wylde's corner wide.
McGinn came close to putting his side in front when his strike hit the post before sub Boerrigter scrambled home for the Hoops from Mulgrew's corner.
Commons then finished from close range after a late breakaway as Celtic's continued their unbeaten start to the season.
Elsewhere, Terry Butcher's first game in charge of Hibernian ended in a goalless draw with St Mirren, Â¬Inverness beat St Johnstone 1-0, Dundee United defeated Partick Thistle 4-1, Motherwell won 2-0 against Kilmarnock and Hearts drew 2-2 with Ross County.