Lotus ART's Valtteri Bottas put his stamp on Round 2 of the GP3 Series by setting the quickest time in Practice 1 this morning at Circuit de Catalunya in Istanbul with a lap of 1:38.726.In stark contrast to the opening GP3 round two weeks ago in Istanbul, the teams were greeted today with sunny and hot conditions at the Spanish track. As the morning session got underway, all thirty cars hit the track as soon as the pitlane opened. Marussia Manor Racing's Rio Haryanto was the first driver to put in a lap, but it was MW Arden's Lewis Williamson who led the way for the first half of the session. The Brit went top with a 1:39.665 lap ahead of Atech CRS GP's Marlon Stockinger, Marussia Manor Racing's Matais Laine and Tech 1 Racing's Tamas Pal Kiss.Waved yellow flags briefly slowed down proceedings when Antonio Felix Da Costa lost a wheel from his Status Grand Prix car and stopped out on track. As the second half of the session got underway, MW Arden's Mitch Evans went quickest, but Bottas pushed hard in his Lotus ART machine and moved to the top of the time sheet nudging the New Zealander into second spot. With ten minutes left on the clock, Bottas stayed top ahead of Evans, teammate James Calado, Haryanto, Williamson and Addax Teams' Dean Smith. Tech 1 Racing's Antonio Caldarelli moved up into 7th.With the chequered flag in sight, Evans went for one more last ditch attempt to go top, but he hit traffic and was unable to improve his personal best time. As so the session ended with Bottas top ahead of Evans, Calado, Haryanto, Williamson, Smith, Caldarelli, Series leader Nigel Melker, Aaro Vainio and Pedro Nunes rounding out the top 10.