The 23-year-old Guillen hit 73 while captain Rayad Emrit (61), Sunil Narine (58) Kevon Cooper (56) and Deepak Kumar (52) all added fifties to guide defending champions North to an impressive 384 for nine at the close of the first day of the four-day match, traditionally used as a trial game in helping to select the national squad.
Guillen stroked 11 fours and two sixes off 75 balls in 105 minutes at the crease and shared a first wicket stand of 99 with Mario Belcon who hammered 41 from 60 balls with six fours.
When North stumbled to 131 for five, Emrit and Cooper combined in a 112-run, sixth wicket partnership to bail their side out of trouble.
Cooper’s half-century came in 69 minutes from 59 balls with six fours Emrit raised his landmark in 65 minutes off 55 balls with five fours and two sixes.
North again lost their way, slipping to 269 for eight but T&T hopeful Sunil Narine and debutant Deepak Kumar featured in a 106-run, ninth wicket stand that frustrated the South bowling attack.
Kumar was dismissed shortly before the close after facing 114 balls, in 134 minutes and stroking eight fours while Narine was unbeaten on 58.
Spinner Dave Mohammed (3-79) and Amit Jaggernauth (3-83) were the top bowlers for South, while pacer Shannon Gabriel chipped in with two for 56.
