Vietnam's No.1 chess player Le Quang Liem defeated Ukrainian Ruslan Olegovich Ponomariov in their fifth meeting at the 39th Super Grandmaster Chess meet in Dortmund, Germany on Tuesday.
The 10th-ranked Ponomariov is the event's reigning champ and the 27th-ranked Liem was the only one competitor who beat him at last year's contest, in which Liem finished second.
Liem played white for the first time in the tournament and took advantage of the opportunity to launch a long series of relentless attacks.
Ponomariov's defense proved strong, but Liem -- the only Vietnamese player to ever enter the world's top 100 -- only played better as the game progressed.
After 71 moves, Liem defeated Ukraine's second best player after a nearly six-hour battle.
The win helped Liem extend his undefeated streak to five (with four draws) and lifted him to second place with three points, pushing Ponomariov to third with 2.5 points.
World number five Vladimir Borisovich Kramnik is leading the contest with 4.5 points.
In the next round, Liem will play white against German Georg Meier, who is currently ranked 90th in the world.