Sometimes there is more excitement to be found in Coventry on a Sunday afternoon than in some allegedly more glamorous distant time zone. This eventful grapple-fest certainly provided enough drama to satisfy anyone’s entertainment tastes, particularly those associated with a Harlequins team who became the first visitors in almost two years to topple previously unbeaten Wasps at home in the league.

Before this spicy contest, Wasps had reeled off 20 straight home Premiership victories dating back to December 2015 and they will be kicking themselves not to have extended that sequence. What had looked set to be another Danny Cipriani-orchestrated triumph ended up with Quins’ precocious 18-year-old Marcus Smith holding aloft the man-of-the-match medal as Cipriani limped away behind him nursing a sore knee and a sizeable dollop of injured pride.

With a rerun of last season’s final looming in Exeter next Sunday, Wasps’s most urgent need is to work on their composure. The high-profile spat between Lions and England colleagues James Haskell and Joe Marler that resulted in the former being sent to the sin-bin for grabbing the prop by the throat was indicative of Quins’ desire to get under their opponents’ skins and, assisted by Cipriani’s 67th-minute yellow card for a deliberate knockdown, they stayed calm enough in the final quarter to record their first away league win since March.

Given the presence of Eddie Jones, the England coach, it was not the worst moment for Smith to underline his obvious promise with the two final-quarter penalties that helped Quins over the line after their forwards had appeared to be on the retreat following the dispatch to the sin-bin of another combustible Lion, Kyle Sinckler, for dragging down a maul.

They have not been prolific winners on the road and their director of rugby, John Kingston, could not hide his delight: “The next time we play away we can reference the fact we’ve taken the castle at the Ricoh. We refused to take a backward step in any way, shape or form.”

When Wasps’ director of rugby, Dai Young, looks back at the array of “wasted opportunities” his side contrived to blow at key moments, in contrast, he will be even more frustrated than he was by the string of refereeing decisions against his side. “Obviously we could have won it but we weren’t clinical enough,” Young lamented. To make matters worse, in addition to Cipriani’s currently undiagnosed knee problem, Alex Rieder has a suspected dislocated shoulder and Guy Thompson suffered a dead leg.

There was more tasty action in the first 40 minutes alone than in all of this weekend’s assorted club overseas jaunts combined. Wasps went in 13-11 ahead at the interval but should have been much further in front. When their hooker Tom Cruse broke through early on with an array of try-scoring candidates on either side of him and unaccountably failed to pass to any of them it started an unfortunate trend.

To Cruse’s relief, Wasps did soon score on the other side of the pitch, a lovely subtle little surge from Cipriani putting Marcus Watson clear before Willie le Roux fed Christian Wade for the kind of dagger-sharp score their supporters have grown accustomed to.

In Marland Yarde, however, the watching Jones has another autumn wing candidate who has made an even stronger start to this campaign. Wasps will be slightly disappointed by some of the defensive positioning that allowed Mike Brown to rise and tap down Smith’s clever 23rd-minute cross-kick but Yarde was in the perfect place to gather and score.

The winger was also crucially involved when another sleek Wasps attack, launched by another nice change of gear from Cipriani, led to Le Roux freeing Watson for what should have been a classic winger’s try. Just as last year’s GB sevens Olympic silver medallist was diving for the corner, however, the ball slipped from his hands as Yarde bravely arrived for the cover tackle. Wasps’ forwards, who had their visiting counterparts under increasing pressure, had every reason to curse under the breath.

It was much the same after the break. Neither Young nor his fellow former prop Kingston are the most svelte of head coaches but their teams both possess the ability to dazzle, not least when Quins expertly exploited the tiniest of 44th-minute overlaps on the left and Charlie Walker exchanged passes with Joe Marchant to put his side 18-13 up.

Surely Wasps could not muck up this one? It seemed not when Quins, having escaped another near-certain try after Le Roux slipped out of Danny Care’s tackle, saw Sinckler rightly shown a yellow card and Cruse partially atoned for his earlier error by crashing over from Wasps’ next lineout drive.

Cipriani, though, could not land the angled conversion, leaving the scores tied at 18-18 and rain making the ball greasier. The fly-half’s third penalty goal of the day did put the hosts ahead with 18 minutes left but his fatal flap at a ball he had little chance of catching proved extremely costly. Smith, the supposed apprentice, stepped up to floor his more experienced wizard and ensure that, after only three rounds, there remain no unbeaten teams in the Premiership.

Wasps Le Roux; Wade, Daly, Lovobalavu, Watson (Miller, 69); Cipriani, Simpson; Mullan, Cruse, Cooper-Woolley (Moore, 60), Launchbury (capt), Symons, Rieder (Haskell, 11), Thompson (Johnson, 32), Hughes.

Tries Wade, Cruse. Con Cipriani. Pens Cipriani 3.

Sin-bin Haskell 20, Cipriani 67.

Harlequins Brown; Yarde, Marchant, Roberts, Walker; Smith, Care; Marler (Lambert, 48), Ward, Sinckler (Collier, 64), Merrick (Glynn, 61), Horwill (capt), Robshaw, Clifford, Luamanu (Collier 57-64).

Tries Yarde, Walker. Con Smith. Pens Smith 4.

Sin-bin Sinckler 54.

Referee A Jackson. Att 15,308.