A hat-trick by former international Len Aiyappa and three goals by striker Amar Aiyamma enabled Karnataka XI beat ASC Bangalore 6-3 and storm into the semi-finals in the 81st Murugappa-MCC hockey tournament in Chennai on Wednesday.

Karnataka XI will take on Indian Railways, who, in an earlier match, beat Indian Overseas Bank 6-4 via the tie-breaker.

Bald-pated Aiyappa, considered no longer fast enough to do duty for the country, stole the thunder, recording his second hat-trick of the tournament, scoring the second, third and fourth goals after Amar Aiyamma put Karnataka ahead and ASC drew level 1-1 through captain Asif Ali.

All the action unfolded in the second-half after the teams went into the break on equal terms. First Aiyappa, with his characteristic drag-flick, forced a 2-1 lead for Karnataka. ASC drew level when Suresh hoodwinked the Karanataka defence, trapping S V Sunil's pass on top of the circle.

However, Aiyappa turned out to be the toast of Karnataka when he converted two more penalty-corners in the 39th and 41st minutes to see the team lead 4-2.

ASC did not throw the towel in. Pressing good counter-moves, they reduced Karnataka's lead (3-4), again through Asif Ali, who struck following a penalty-corner.

But as the nail-biting contest continued, Karnataka took charge again, attacking relentlessly from the flanks. Aiyamma exhibited his prowess by converting a penalty stroke, awarded in the 58th minute when Anup Anthony was fouled by ASC's Pradeep Singh inside the circle.

Three minutes later, Aiyamma struck again off a left flank move.

Earlier, Indian Railways rallied brilliantly in the tie-breaker to edge out a fighting young Indian Overseas Bank (IOB) 6-4 after being held to a 1-1 draw in the regulation time.

In a match of swift moves and counter-moves, IOB forced the lead against the run of the play in 30th minute. Into the second session, Railways levelled through captain Chander Pal in a three-pronged move on the left flank with international Rajiv Mishra and Vijay Alphonso.

But from then on, the fast-paced contest failed to produce any goals right till the extra-time of seven-and-a-half minutes each for the golden goal. This necessitated the tie-breaker, in which Railways proved stronger, converting all five pushes through Rajiv Mishra, Jagmohan Singh, Bikramjit Singh, Chanderpal and Gursev Singh.

For IOB P U Iyappa, D Felix and D Muthukumaran managed to score.