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The high frequency peaked BL Lac PKS 2155-304 with a redshift of z=0.116 wasdiscovered in 1997 in the very high energy (VHE, E >100GeV) gamma-ray range bythe University of Durham Mark VI gamma-ray Cherenkov telescope in Australiawith a flux corresponding to 20% of the Crab Nebula flux. It was later observedand detected with high significance by the Southern Cherenkov observatoryH.E.S.S. Detection from the Northern hemisphere is difficult due to challengingobservation conditions under large zenith angles. In July 2006, the H.E.S.S.collaboration reported an extraordinary outburst of VHE gamma-emission. Duringthe outburst, the VHE gamma-ray emission was found to be variable on the timescales of minutes and with a mean flux of ~7 times the flux observed from theCrab Nebula. Follow-up observations with the MAGIC-I standalone Cherenkovtelescope were triggered by this extraordinary outburst and PKS 2155-304 wasobserved between 28 July to 2 August 2006 for 15 hours at large zenith angles.Here we present our studies on the behavior of the source after itsextraordinary flare and an enhanced analysis method for data taken at highzenith angles. We developed improved methods for event selection that led to abetter background suppression. The averaged energy spectrum we derived has aspectral index of -3.5 +/- 0.2 above 400GeV, which is in good agreement withthe spectral shape measured by H.E.S.S. during the major flare on MJD 53944.Furthermore, we present the spectral energy distribution modeling of PKS2155-304. With our observations we increased the duty cycle of the sourceextending the light curve derived by H.E.S.S. after the outburst. Finally, wefind night-by-night variability with a maximal amplitude of a factor three tofour and an intranight variability in one of the nights (MJD 53945) with asimilar amplitude.

High zenith angle observations of PKS 2155-304 with the MAGIC-I telescope