Given the last outings of Neptunes Vodafone and Sirens Ritter Sport, no-one would have blamed the pundits for putting their money on a win for the Balluta team.
However, the northerners produced a remarkably gritty display of waterpolo, charted diligently in tactical terms and executed admirably in the water.
Indeed, this was a victory which should give heart to Sirens whose ruthless press, although costly in expulsion terms, ironically proved productive. With Karl Montfort back in the side Sirens must have also had a psychological boost.
Tamas Marcz's effective shadowing on Steve Camilleri and some well-taken goals, especially from Charlie Zammit at crucial moments, also helped Sirens' cause.
For the Reds, this was a forgettable match. They simply did nothing right, possibly showing overconfidence and in the process, only scoring once from nine man-ups, something which is becoming an endemic flaw in their game.
It was 2-2 after the first session when it was evident that Sirens went for stringent all-pitch press. They inflicted further damage on the Reds in the second when they took a 5-2 lead as Neptunes started their saga of missed man-ups.
Paolo Malara called a time-out to try and bring sanity into the Reds' game. It was to no avail as Sirens remained firmly in control to go into the last session 7-3 ahead.
At this point, the northerners may have been caught between crosswinds of administering their four-goal cushion and not forsaking their positive play. With Neptunes fumbling more man-ups, it was distress signals from the muted Reds' clan who could only see their team stumble to an unexpected defeat.
Sirens, under the able stewardship of John Farrugia, had given the Reds a lesson in efficiently solid waterpolo.
In an earlier match, Exiles Jet Services easily beat Otters by 17 goals to five. Their edge in speed and power was translated into this comfortable victory, with the Gozitan team only made to fight in order to restrict the damage.
From the third session onwards, it was an even easier ride for the Sliema team for whom Aurelien Cousin was in the background even if he scored twice.
Neptunes 5
Sirens 9
(2-2, 0-3, 1-2, 2-2)
Neptunes: N. Gouder, N. Lanzon, T. Agius, K. Galea, E. Cachia 1, R. Sciortino, S. Camilleri, J. Camilleri, A. Kunac 1, S. Gravina, L. Sottani 2, M. Stellini, M. Pisani 1.
Sirens: J. Sammut, A. Baranyi 1, A. Galea 1, P. Privitera 2, A. Attard, R. Mock, J. Borg 1, D. Cutajar, K. Montfort, C. Zammit 2, C. Mercieca, T. Marcz 2, J. Cremona.
Referees: I. Sciriha, A. Severo.
Otters 5
Exiles 17
(3-6, 1-3, 1-4, 0-4)
Otters: R. Grech, D. Saliba, G. Zammit 1, S. Grech, K. Scicluna, P. Szabo 1, K. Mizzi, C. Baco 2, S. Dimech, L. Cachia, A. Arrigo 1, S. Xerri, C. Martin.
Exiles: A. Borg Cole, J. Rizzo Naudi, K. Rizzo Naudi 3, D. Pace Lupi, T. Sullivan 3, S. Cini 2, R. Chomakhidze 3, K. Griscti 1, A. Zarb Cousin, A. Cousin 2, S. Vassallo, K. Enriquez 1, M. Calleja 2.
Referees: S. Licari, M. Caruana.
Today: 19.30 San Ġiljan vs Sliema.
Tomorrow: 18.15 San Ġiljan vs Marsascala; 19.30 Neptunes vs Ta' Xbiex.