The American player led by half-a-point from his nearest challenger heading into the ninth round of competition, as he looks to earn the right to face Norway's world champion Magnus Carlsen in London later this year.

Caruana appeared on course to claim victory over China's Ding Liren today.

He would ultimately fail to convert his opportunity into a win, however.

The draw sees him move to six points in the overall standings.

It means he failed to take advantage of Azerbaijan's world number two Shakhriyar Mamedyarov being held to a second successive draw.

Armenia's Levon Aronian, who began the day bottom of the group, was able to frustrate Mamedyarov.

Mamedyarov still lies second on five-and-a-half points in the standings.

Alexander Grischuk is third on five points, after the Russian drew with American player Wesley So.

Sergey Karjakin claimed victory in an all-Russian match with Vladimir Kramnik, the early front-runner who arrived in this event on a wildcard.

Karjakin, who lost the last world final to Carlsen on a tie-break two years ago, lies fourth overall on four-and-a-half points.

The event, due to last until March 28, is being contested as a double round-robin with each player playing 14 games, seven with white pieces and seven with black.

A top prize of €95,000 ($117,000/£85,000) is on offer for the winner.

There is a rest day tomorrow.