The regime may have changed at Wasps during the summer, with Ian McGeechan replacing Warren Gatland as director of rugby, but the champions picked up where they left off at the end of last season with a win at HQ.
Wasps were twice forced to come from behind but tries from Tom Voyce and the faultless kicking of Mark van Gisbergen – three penalties and two conversions – gave them the advantage as the clock ticked down.
And the victory was eventually sealed by Waters, the England centre, who came off the bench to score under the posts in added time.
Saracens, who also finished last season triumphant at Twickenham as they won the now defunct wildcard play-off to claim a spot in the Heineken Cup, opened an early lead as Glen Jackson landed two quick penalties.
They were powerful in the tight, driving Wasps backwards and causing problems in the scrum, but barring the odd flash of individual menace from their French full-back Thomas Castaignede, lacked the creative touch.
Saracens are waiting on Andy Farrell, who was out for the third week running with a toe injury, to perform exactly that role.
They want him to inject a natural flair into their game as second receiver and he will more than likely bolster their midfield defence which was opened up too easily by the hard-running Ayoola Erinle.
Wasps played all the football early on and fly-half Alex King almost found space down the right wing but was bundled into touch. Saracens hooker Matt Cairns then missed his jumpers in the two-man line-out and almost handed Wasps another chance.
The ball was claimed by Matt Purdy but he ran head-first into the solid form of Saracens prop Cobus Visagie on the line and lost the ball forward as he collapsed to the deck with a serious cut to the head.
Van Gisbergen reduced the arrears with his first shot at goal after 26 minutes and Wasps began to crank up the pressure. Joe Worsley launched a perfect kick which pinned Saracens back into their own 22 and Voyce jinked his way through a busy but broken defensive line to earn Wasps the lead.
Van Gisbergen converted and then produced a try-saving tackle on Castaignede after Jackson’s lofted pass to Richard Haughton had opened the space. Jackson failed with an attempted drop-goal and only last-ditch defence from Saracens preserved the 10-6 scoreline at half-time.
Raphael Ibanez, Wasps’ summer recruit from Saracens, turned on the gas and fed
Sackey outside him but the winger was held up over the line in the last action of the half.
Saracens, whose season was transformed last year when the no-nonsense Steve
Diamond took charge, started the second half the quickest and number eight Ben
Skirving galloped through Sackey’s challenge and over for a try inside three minutes of the restart.
Jackson missed the touchline conversion but Van Gisbergen was spot on with two penalties from distance as Wasps worked themselves back into the lead. Lions and England scrum-half Matt Dawson came off the bench with 15 minutes remaining and began to direct traffic brilliantly as Wasps camped inside the Saracens half.
Wasps worked the space expertly and Waters delayed his pass perfectly for Sackey who contrived to spill the ball with the line one pace away.
It was a clanger of major proportions, reminiscent of Ben Kay’s drop in the World Cup final. His heart will have been in his mouth as Saracens tasted blood and launched themselves downfield. But Wasps held on heroically before Sackey swept up a loose ball and sparked an 80-metre counter-attack.
Haughton caught him before the line but Kevin Yates came flying in after the whistle had blown for a knock-on. The Saracens prop was sin-binned, leading to uncontested scrums. Stuart Abbott ignited another Wasps attack with the initial break and then fed Waters to seal the victory.