United’s Italian owner joined a crowd of 2,200 for a tight and even contest which played out in wet and humid conditions and was settled by late goals from Jason Pearce and Matt Smith.
Cellino had taken his players and staff out for lunch in Leeds prior to their first domestic friendly of the summer and Pearce and Smith delivered a victory in return after a long spell in which Guiseley frustrated United.
Head coach David Hockaday stretched the legs of his starting line-up by playing them for an hour, using new signings Marco Silvestri, Tommaso Bianchi and Souleymane Doukara from the outset.
Gaetano Berardi’s move from Sampdoria yesterday evening was processed too late for the Swiss right-back to play but he travelled with the squad to Nethermoor and could make his debut at Mansfield Town on Tuesday, the first of United’s friendlies against Football League opposition.
Guiseley are four rungs below Leeds in the English pyramid but this afternoon’s match was still the most competitive staged by the Championship club so far following a 16-0 rout of an amateur side in Italy last week and the cancellation of a planned meeting with Romanian side Vittorul Constanta.
Guiseley’s team included two familiar names - ex-Leeds left-back Ben Parker and Gavin Rothery, once a promising member of United’s academy at Thorp Arch - and the non-league side made a tight contest of the first half.
Leeds saw only two clear chances, with Steve Morison heading a Charlie Taylor cross into the side-netting and Bianchi forcing an excellent, one-handed save from Steve Drench with a curling shot from outside the box.
Danny Forrest could have scored at the other end, however, and his rising shot forced Silvestri to tip the ball over with his fingertips.
Jake Lawlor should have opened the scoring for Guiseley at the start of the second period but dinked the ball wide of an exposed goal and Silvestri stood up well to claim a rising effort from Rothery.
Doukara saw a rare chance deflected shortly before Hockaday introduced a different line-up for the last 30 minutes and Leeds were denied a penalty when Aidy White’s cross struck the arm of Ryan Toulson
Lewis Walters almost snatched the opening goal when his strike on the turn on 74 minutes was beaten away by Drench but the keeper’s failure to read a corner from White on 85 minutes left Pearce with the task of heading into an empty net.
And Smith sealed the victory five minutes later when he ran in to covert Sam Byram’s cross from point-blank range.
Guiseley: Drench, Holdsworth, Parker, Lowe, Hall, Lawlor, Brooksby, Stockdill, Boyes, Forrest, Rothery. Subs: Toulson, O Johnson, Harrison, Ible, Porritt, Crossley, Marshall, Walker, Scott.
Leeds United: Silvestri (S Taylor 60), Thompson (Byram 55), Lees (Wootton 60), Killock (Pearce 60), C Taylor (Warnock 60), Cook (Austin 60), Tonge (Murphy 60), Bianchi (White 60), Norris (Hunt 60), Morison (Walters 60), Doukara (Smith 60).