Zurich, Feb 15 (PTI): Former world champion Viswanathan Anand played out two draws to keep his full point lead in the Zurich Chess Challenge here.

After two wins against Levon Aronian of Armenia and Dutchman Anish Giri, Anand wriggled out of problems against Latvian Alexei Shirov in the third round game and then played out a draw with Hikaru Nakamura of United States to stay afloat in the Classical-Rapid section.

With two points for a victory and one for a draw, Anand took his tally to six points overall and will have white pieces against Vladimir Kramnik of Russia in the final round of the Rapid section.

After the last round, the players will change gears and enter a blitz play-off wherein one point will be awarded for a win and half a point for a draw.

Nakamura and Kramnik share the second spot on five points apiece. While the American also drew both his games, Kramnik was a class act against Giri in the fourth round that gave him a chance to jump to the joint second spot.

Aronian on three points is sole fourth in standings while Giri and Shirov are at the bottom of the tables with two points apiece.

The third round witnessed no decisive results despite keenly-contested affairs. Anand was pitted against Shirov and it was the most dramatic game of the round.

The Latvian fianchettoed his dark squared Bishop in the Spanish opening and sacrificed an exchange and Anand was in some troubles as all black pieces spat fire on board.

However, some deft manoeuvres by Anand ensured parity after the Indian gave back his rook for a minor piece and the onus was on Shirov to find some finesse in the final stages to force a draw.

In the other games of third round, Kramnik drew with Nakamura wherein the latter had to put up a splendid defense while Aronian also achieved the same result against Giri.

The fourth round was most crucial for Anand as he had black against Nakamura but the Indian ace was seen pressing with black pieces out of a reverse Grunfeld.Nakamura sacrificed a pawn and reached a Rook and opposite colours Bishop endgame to force a draw in the end.

Kramnik's win against Giri came in a Reti opening while Aronian subdued Shirov for his first win in the tournament.

In the final round now, Anand will have white pieces against Kramnik while Nakamura plays with black against Aronian. A draw should be enough for Anand to clinch the Rapid title here.

Results round 4: Hikaru Nakamura (Usa, 5) drew with V Anand (Ind, 6); Vladimir Kramnik (Rus, 5) beat Anish Giri (Ned, 2); Alexei Shirov (Lat, 2) lost to Levon Aronian (Arm, 3).

Round 3: Shirov drew with Anand; Nakamura drew with Kramnik; Aronian drew with Giri.