Mariano, an Armyman, essayed his favorite Chameleon variation against the Sicilian defense of Kuzmin to split the point in 41 moves as the former Asian Junior champion remained the highest-placed Filipino in the tournament with four points after six rounds.
GM Bong Villamayor failed to exploit his edge with the white pieces and was held to a draw by FIDE Master Vlad Barnaure of Romania in 50 moves of a Reti Opening and was half-point behind Mariano with 3.5 points.
IM Barlo Nadera absorbed his second loss after GM Viorel Iordachescu of Moldova dismantled the Filipino’s pet French Defense, forcing the former to resign in the 39th move by threatening to either mate or secure a rook.
The setback dampened the chances of Nadera of securing a GM norm since he was to win more points in the remaining three round due to the lower rating of his succeeding foes.
He faces R.B. Ramesh of India, rated 2493, in round 7.
Mariano goes up against GM Mikheil Mchedlishvili of Georgia, rated 2543 against the Filipino IM’s 2416 rating.
Villamayor plays white against 12th seed GM Evgeny Gleizerov of Russia, rated 2592 against Villamayor’s 2469.
Six players remain in the lead with 5 points apiece, namely GM’s Liviu-Dieter Nisipeanu of Romania, Shakriyar Mamedyarov of Azerbaijan, Krishnan Sasikiran of India, Artashes Minasian of Armenia and Pavel Eljanov of Ukraine.
Ten GM follow with 4.5 points each while Mariano was in the next rung below in a deadlock with 15 others.
A total of 45 grandmasters head the field of 134 players from 39 countries competing in the sixth edition of the Dubai Open which has grown to become the strongest open chess tournament in Asia.