The brother-sister Indian duo of Rameshbabu Praggnanandhaaa and Rameshbabu Vaishali suffered defeats in their respective section, while Magnus Carlsen justified his top billing with a win over an off-colour Ding Liren to surge to sole lead on 12 points in the Norway Chess tournament in Stavanger.
Fabiano Caruana also scored over compatriot Hikaru Nakamura to help Carlsen emerge as the front runner for the crown in the six-player double round-robin contest being fought for a total prize pool of US$ 161000.
Pragganandhaa lost to Firouzja Alireza of France in the Armageddon tiebreaker after suffering a bit through the Classical game too while Vaishali went down to World women's champion Wenjun Ju of China who outplayed the Indian in the endgame.
With four rounds still to come in both sections, Carlsen is now followed by Nakamura on 11 points while Praggnanandhaa is still third on 9.5 points in all.
Alireza is on fourth spot with eight points in all and Caruana follows him with 6.5 points. Surprisingly, China's Ding Liren seems completely out of sorts with just 2.5 points thus far, needing a miracle to come back in the tournament.
In the women's section, Wenjun snatched the lead from Vaishali along with Anna Muzychuk of Ukraine who won a hard-fought Armageddon against Tingjie Lei of China. Both Wenjun and Muzychuk have an identical 10.5 points, a half point ahead of Vaishali.
Lei is fourth on seven points, enjoying a two-point lead over Koneru Humpy who suffered another loss at the hands of Pia Cramling of Sweden in the Armageddon.
Cramling has 4.5 points now and is still at the bottom of the tables.
Gaining a small advantage out of the opening, the world number one Carlsen capitalised on his double Bishops to launch an offensive on the king side and used another blunder by Ding Liren to finish the game with a child-like queen sacrifice.
Liren looks a far cry from the man who won the last World championship title against Ian Nepomniachtchi of Russia and needs to really gather himself to make a match of it in the next edition of the tournament against India's Dommaraju Gukesh.
Currently, as per FIDE, the apex governing body, there are bids from Delhi, Chennai and Singapore to hold the World Championship match.
Praggnanandhaa suffered a jolt in his quest as Alireza played a nice game under Classical to put pressure and eventually drew the contest. In the return game however, the Indian faltered and could not really stage a comeback.
In the women's section, Vaishali had her chances but Wenjun Ju was at her technical best and seized opportunities as they came her way. The minor pieces endgame had some chances but Vaishali could not sustain the pressure.
Results:
(Men)
Magnus Carlsen (Nor, 12) beat Ding Liren (Chn, 2.5) 3-0; Hikaru Nakamura (USA, 11) lost to Fabiano Caruana (Usa, 6.5) 1-1.5; Firouzja Alireza (Fra, 8) beat R Praggnanandhaa (10) 1.5-1.
(Women)
R Vaishali (Ind, 10) lost to Wenjun Ju (Chn, 10.5) 0-3; K Humpy (Ind, 5) lost to Pia Cramling (Swe, 4.5) 1-1.5; Anna Muzychuk (10.5 beat Tingkie Lei (Chn, 7) 1.5-1).
