Ryan Mills kicked eight penalties as Aviva Premiership champions Saracens crashed to a shock 24-18 defeat at Sixways.

There was no fluke about the surprise victory as the hosts rattled their opponents from the start and maintained their aggression and determination throughout.

Saracens were second best in all areas and never looked like winning, as frequent penalties and numerous handling errors stopped them from getting a grip on the game.

The visitors did manage the only tries of the game through Chris Ashton and Schalk Brits, with Alex Lozowski converting one and kicking a penalty.

Ben Spencer added a late penalty. It was a huge win for Warriors, with their success giving them a five-point cushion over bottom club Bristol in the fight against relegation.

Worcester had the first opportunity for points but Mills missed with a long range penalty before he soon made amends with an easier chance after Schalk Burger was penalised for a high tackle on Chris Vui.

Warriors maintained their momentum throughout the first quarter as the visitors conceded regular penalties to find themselves penned in their own half. Uncharacteristic kicking errors from Matt Gallagher and Richard Wigglesworth did not help Saracens' cause either - and they trailed 3-0 after a poor opening 20 minutes.

Two minutes later, the hosts' dominance was rewarded with a second penalty from Mills and some astute kicking from him kept Saracens firmly on the back foot. Out-of-sorts Saracens then suffered a further setback when Mike Ellery was yellow carded for a dangerous late challenge on Francois Hougaard, which left the Springbok scrum-half in a crumpled heap.

Ellery was perhaps fortunate that the card was not red but Mills kicked the resultant penalty before Saracens reached the home 22 for the first time in the 35th minute and were immediately rewarded with the first try of the game.

A clever kick through from Wigglesworth saw Ashton narrowly win the race for the touchdown. Lozowski converted but a fourth penalty from Mills gave his side a deserved 12-7 half-time lead.

Saracens prop, Petrus Du Plessis was replaced at the interval by Juan Figallo before Lozowski failed with a penalty just after the restart.

Worcester suffered an injury when promising hooker Jack Singleton was helped off with a leg injury to be replaced by Georgian international Jaba Bregvadze but they overcame this to extend their lead with an excellent long range penalty from Mills.

Lozowski kept Saracens in contention with his first penalty as his side were more competitive in the third quarter but two further penalties from Mills kept Worcester 21-10 ahead at the end of it.

Saracens became increasingly frustrated and conceded an eighth penalty before Brits finished off a driving line-out for a consolation try, with Spencer's last minute penalty giving the visitors a scarcely-deserved bonus point.