Defending Aviva Premiership Rugby champions Leicester survived a huge scare to recover from 11 points down with 16 minutes remaining to beat top-flight new boys Exeter at a mightily-relieved Welford Road.
The Chiefs had won their first-ever top-flight fixture against Gloucester last weekend but few gave them any chance against a Tigers side that had lost just once in 34 home games.
But Rob Baxter's side refused to be intimidated by their big-name opponents and deservedly led 20-10 at the interval after two fine tries from centre Phil Dollman and two penalties and two conversions from kicking prodigy Gareth Steenson.
Geordan Murphy had claimed the first try of the match for the stunned Tigers, whose line-out at times bordered on the shambolic. Jeremy Staunton converted and added a penalty before the break. Staunton, who ended with 17 points, kicked two penalties early in the second half to cut the gap but a fine solo try from wing Mark Foster saw Exeter stretch away.
But Leicester showed trademark resolve and summoned converted tries through Scott Hamilton and Dan Hipkiss to turn the game around in the space of five minutes, with a late penalty try ensuring they avoided starting a league season with back-to back defeats for the first time.
Fly-half Steenson, who kicked 17 points in the win over Gloucester, gave the visitors a third-minute lead with a penalty after an impressive rolling maul by his forwards. Leicester responded in ferocious fashion, working their way into the Exeter 22 and battering away at the line.
The pressure told as lock James Hanks was sin-binned after straying offside. Leicester opted to take a scrum rather than a shot at goal and were rewarded as number eight Thomas Waldrom sucked in the defence before some sharp handling put skipper Murphy over for a 12th-minute try, converted by Staunton.
To their credit, Exeter continued to look to keep the ball in hand and some patient build-up was rewarded with a second Steenson penalty to make it 7-6. Hanks returned from the bin and the Chiefs proceeded to stun Welford Road with a well-worked score. Steenson freed wing Foster down the right and his inside ball saw Dollman evade the cover defence to go behind the sticks. Steenson's conversion gave the Devon side a surprise 13-7 lead after 25 minutes.
The errors were all coming from the champions as passes went down and line-outs went astray and the visitors capitalised with another lovely try through centre Dollman. Luke Arscott was the provider as he broke through a weak tackle to send Dollman over, Steenson added the extras and the Aviva Premiership Rugby new boys were 20-7 ahead after just 33 minutes.
Staunton kicked a penalty on the stroke of half-time to trim the deficit but the Tigers left the field to boos from a section of their own fans at the break.
Steenson was off target for the first time this season with a penalty attempt early in the second half and the hosts were soon on the comeback trail as Staunton landed two three-pointers of his own in quick succession after intense Leicester pressure.
Exeter did not panic and they continued to show the greater cutting edge as Foster dummied through some paper-thin blindside defence to cross in the corner. Steenson's superb touchline conversion made it 27-16 with just 23 minutes to play.
But Leicester showed why they have won the last two titles with a breathless fightback. First Hamilton finished powerfully in the 64th minute after ignoring the help of replacement prop Marcos Ayerza outside him, with Staunton's conversion trimming the lead to four points.
England flanker Tom Croft, returning from injury off the bench, then went marauding down the right and lovely hands from Waldrom on the opposite flank saw Hipkiss stroll over untouched with Staunton again on target with the extras.
Those tries knocked the stuffing out of Exeter and a series of powerful scrums from Leicester saw referee Dean Richards award a penalty try in the dying seconds to give the Tigers a bonus point and cruelly deny the Chiefs anything after a superb performance.