However, Quins were the "away" side yesterday which meant they had to change in the pink room. Not only that but they had to listen to an incessant performance from two Scottish pipers.
Nevertheless, it was Harlequins, and in particular the metronomic kicking of John Schuster, who called the tune. In fact, there was no lack of aggression and this game was as hard as you would imagine between warring neighbours who are capable of upsetting anybody on their day, particularly each other.
London Scottish had stunned Saracens at Watford last week while Quins made it seven wins out of eight with a dour, forward-obsessed display against Sale here last Sunday.
London Scottish, playing into the wind in the first half, were 6-0 up after eight minutes through penalties from Iain McAusland. The Quins pack raised their game and their relentless driving enabled Schuster, a revelation as a goal-kicker this season, to turn pressure into points.
As the Exiles repeatedly fell offside, Schuster kicked four penalties from the 11th minute to the 28th. With McAusland adding another, London Scottish were slightly fortunate to go in at half-time only three points in arrears.
Just before the interval, in one of the few coherent passages of play, Daren O'Leary went round his opposite number Conan Sharman but was tackled at the corner flag. This was followed by a concerted drive with the entire pack crossing the Scottish line but the referee gave the Exiles the benefit of the doubt. It was probably poetic justice, although there wasn't much poetry about it.
In addition to fierce tackling, another factor which ensured an absence of tries in the first half was wretched handling and passing. Zinzan Brooke took a tap penalty 10 yards from the line and then threw out a dreadful pass which flew two yards behind Dan Luger.
There were also frequent injuries. Both the Quins props, Gary Halpin and Jason Leonard, were in the wars, the latter after colliding with Brooke - never a wise move.
A surreal hailstorm at half-time, as blue skies gave way to black with lightning in the air, delayed the reappearance of the teams. Normal service was resumed when Schuster landed his fifth and sixth penalties before the first try arrived in the 61st minute. From a scrum near the Scottish line, Chris Sheasby picked up, attacked on the blind side before feeding the scrum-half Huw Harries who crashed over. It was the signal for a rousing finale. Six minutes later a chip ahead from Jan Bonney fell kindly for the right wing Kenny Milligan who took the opportunity with skill and pace to score near the posts.
Simon Forrest, who had come on as a replacement for McAusland, missed the simple conversion. However, he kicked a penalty nine minutes from time to make it 17-23 before Brooke smuggled his way over from another big Quins drive.
In the dying minutes Rob Hunter, the Scottish No 8, replied in kind and in the final move the impressively mobile Halpin scored Quins' third try to seal victory.
It was a bitter defeat for London Scottish, who earlier in the season were defeated 22-20 by Harlequins. That was the start of Harlequins' eloquent run following an awful start to the season. Now, with eight victories from their last nine matches, the former soft touches of London rugby have become serious contenders.
London Scottish: I McAusland (S Forrest, 47 min); K Milligan, J Bonney, R Eriksson, C Sharman; B Irvine (R Davies, 57 min), G Easterby (S Cook, 70 min); P Johnstone, D Cummins (D Rudham, 40 min), P Burnell, E Jones, M Watson, S Fenn, R Hunter, S Holmes (capt).
Harlequins: J Williams; D O'Leary, J Schuster, D Officer (J Keyter, 75 min), D Luger; T Lacroix (capt), H Harries (N Walshe, 67 min); J Leonard, T Murphy (C Ridgway, 73 min), G Halpin, G Llewellyn (B Davison, 67 min), G Morgan, Z Brooke, C Sheasby, A Leach.
Referee: S Savage (RFU).