Last season's top two kicked off the season in opposition to last season's bottom two. Bath duly completed the expected, joining Northampton with a bonus-point win to open their account. The team the Saints succeeded as champions last season travelled to the Stoop to remind Harlequins how much more they have to work on if they are to return to the sort of form that made them champions not so long ago.

The home team took to the field with a host of absentees, it is true. No Marcus Smith; no Alex Dombrandt; no George Furbank, a new signing with a shiny champion's gong around his neck. They were bright as they always are, but the substance of their visitors was too much in the end, leavened by a flash of genius by the Argentinian Santi Carreras that will long stay with all who witnessed it. To boast that sort of muscle, to boast that sort of genius, Bath will take some beating again this season.

They had the bonus point by half-time, which felt a bit harsh on a Quins team that had enjoyed plenty of bright moments. Their challenge, it seems again, will be to find the composure to fill in the stretches of time between them with something substantial. As it is, they flare up from time to time with a flash of brilliance. Bath have more in the way of relentless intensity. And they have Carreras. And Finn Russell, of course. But of the two geniuses it has been Carreras turning heads of late, apparently playing in training as if he were, to quote his coach, the best player in the world.

The cruellest turning point of the match was courtesy of a moment that might as well have been in training it was so casually, instinctively of another planet, might as well have been conjured by Maradona or Messi. The ledger read two tries apiece on the half-hour when Quins had just worked another of their sparks.

Tyrone Green was homing in on Carreras, the last man, with Oscar Beard outside him. Nothing wrong with the pass. But a dilemma for the last man in those circumstances is always whether to stick out a hand for the interception and risk a penalty try if it knocks on? Carreras supplied the answer. Use your foot. Green's pass fizzed across him and he flicked up his boot to volley the ball sweetly into the air, coolly ran on and reached one hand over the touchline to regather it from the air. And on he ran to the tryline some 75 yards away. Did we mention he is also seriously quick?

"In my view that is going to be try of the season for us in round one," said the Bath head coach, Johann van Graan. "What a player, what a moment." That meant it was to be Bath, not Quins, who would be the first to score a third try. Suddenly it was 21-10 to the visitors. More punishing still they scored that fourth try on the stroke of half-time from a penalty to the corner, Dan Frost at the back of an advancing maul, much as Dan du Preez had earlier opened the scoring on his Bath debut.

Joe Cokanasiga hit a hard line for Bath's second, while Harlequins had kept in the match with two of those flashes, first by Will Porter, who went through or round three defenders off loose lineout ball, then when Chandler Cunningham-South ran home after Beard's brilliant turn.

More of the same had Quins their third on the resumption. This time Cadan Murley was away doing his thing down the left. His run established the position; Pedro Delgado's rumble round the fringes finished the job. Quins seemed happier all of a sudden, but their case was not helped by the yellow card shown to Sam Riley a few minutes later for an illegal tackle on Beno Obano.

Bath hardly made it tell. They meandered a little themselves in the third quarter, but when you have set-piece weaponry it is only a matter of time before you get a chance to use it. And so they did, putting the game beyond their hosts in the last 10 minutes, scoring from a driven lineout for the third time, when Ewan Richards finished from another penalty to the corner.

One cloud on the horizon for Bath and England might be Sam Underhill's departure early in the second half. Van Graan is concerned he might have suffered a biceps injury, which would mean months on the sidelines. Otherwise, though, the usual suspects are flexing their muscles into the new campaign.