Skippered by Frenchmen Christophe VANEK and Alain FÉDENSIEU, Horizon had to settle for second place overall after finishing runner up in all five of the first round's five races.
But if the opening exchanges in the 2006 Maktoum Trophy series are a reliable indicator, this year's title battle could be much more than a two boat race.
Swtichblade, skippered by David ROSTANT (UAE), broke TZANOV's winning sequence by claiming victory in the penultimate race to finish third overall and suggest that they could also mount a challenge for the trophy.
After scoring a runaway class 2 success in last year's series, John ROSE (GBR) in Insatiable had to accept second best on this occasion as Gill SMITH (GBR) produce a flawless performance over the two days, with five successive race wins.
Dubai International Marine Club has designed the event to produce highly competitive fleet racing, and has already confirmed that next year's series will be given a new ten day format to attract more overseas challengers.
This year's first round, meanwhile, provided another valuable examination for the V1/Lutra-30 Sport Boat which passed the test with flying colours.
Built by V1 Advanced Composite Technologies at Jebel Ali Free Zone and used competitively for the first time in January's ISAF Grade 3 Dubai Match Race, three V1/Lutra-30s are contesting the series and made a solid start.
One of the V1 boats, Victory skippered by Dutchman Jeroen LEENEN, was narrowly edged out of fourth place by Southern Cross in today's opening race and also finished a creditable fifth in race four, eventually taking sixth place overall.
There was a familiar pattern to the day's opening race, with Pal Zileri winning from Horizon and Switchblade, the same top three as in Thursday's first two races.
It was a different story, however, in race four, as Switchblade came through to grab victory, with Horizon again in second place just ahead of Pal Zileri
Normal service was resumed in the final race, with TZANOV beating out Horizon, and Switchblade again in third.