|Exeter (0) 5|
|Worcester (6) 6|
|Pen: Pennell 2|
Worcester Warriors recorded a first-ever win at Sandy Park, grinding out a one-point victory over champions Exeter Chiefs with a superb defensive display.
Chris Pennell slotted two penalties to put Warriors 6-0 up at the break and might have edged them further ahead but missed a third attempt after half-time.
Chiefs finally registered a score when Mitch Lees grounded the ball after a driving maul proved too strong.
But Gareth Steenson posted a rare missed conversion and Warriors hung on.
Exeter had won all the nine previous Premiership meetings between the two sides, most recently 41-10 at Sixways in September.
But, in a low-scoring game, they suffered their first league defeat at Sandy Park - the cornerstone of their Premiership success - since October 2016.
Without their four-man England contingent, they struggled to open up the dogged visitors, who also had three international absentees, England centre Ben Te'o, Wales winger Josh Adams and Scotland lock David Denton.
Worcester were sharp in line-speed and aggressive at the ruck, swarming to cut off time and space and, even when Chiefs twice made searing line-breaks through Thomas Waldrom and Olly Woodburn, Warriors did enough to shut down the attack.
Warriors scrum-half Francois Hougaard had a fine game sniping from scrum-half, taking the ball to the line and keeping the visitors ticking over from the base of the ruck.
Chiefs remain top of the Premiership, although Saracens can go level with a bonus-point win, while Worcester stay second bottom but extend the gap between them and London Irish at the foot of the table.
Exeter director of rugby Rob Baxter:
"In the Premiership you get the result you deserve and today we deserved nothing.
"It's rare that we only score five points so great credit to Worcester, who were more physical than us and won the breakdown area.
"I don't know how we got so close as they had far more composure than we did for we gave up a lot of ball."
Worcester director of rugby Alan Solomons:
"It was unbelievable and incredible as we managed to operate the key factors in our game plan brilliantly.
"We had to match them physically and our defence was outstanding as we knew we had to take the game in periods of 20 minutes at a time.
"We showed terrific heart as they hold the ball for long passages of play but we thoroughly deserved the win."
Exeter: Turner; Cordero, Whitten, Hill, Woodburn; Steenson (capt), White; Moon, Cowan-Dickie, Holmes, Lees, Hill, Ewers, Armand, Waldrom.
Replacements: Malton, Low, Street, Salmon, Kvesic, Chudley, J Simmonds, Devoto.
Worcester: Pennell; Heem, Willison, Mills, Hammond; Shillcock, Hougaard; Waller, Singleton, Schonert, O'Callaghan (capt), Barry, Faosiliva, Lewis, Van Velze.
Replacements: Haupt, Bower, Milasinovich, Bresler, Williams, Cox, Baldwin, Howe.