Arjun Singh pulled off the biggest upset of the tournament by defeating top seed and defending champion Ashok Kumar 1-up in a pulsating quarterfinal encounter of the SRF all-India Professional Golf Matchplay Championship here on Thursday.

Arjun won the second, fourth, seventh, eighth, 13th, 16th and 18th holes. Ashok lost despite winning the first, third, fifth, 11th, 12th and 14th holes. Arjun had earlier defeated Vijay Kumar on the 20th hole in the pre-quarters in the morning.

In the pre-quarters in the morning, Ashok overcame the R Srinivas 2-up. Naman Dawar ousted second seed Digvijay Singh 1-up.

In the semifinal, Arjun takes on fifth-seeded Lam Chih Bing of Singapore. In the other last-four stage clash, seventh-seeded Shamim Khan faces two-time Indian Open champion Ali Sher.

Lam Chih Bing recorded an emphatic 6 & 5 win over Manav Jaini in the quarterfinals. The Singaporean won the third, fifth, sixth, seventh, ninth and 13th holes.

Shamim made it to the last four after defeating Dawar 5 & 4 in the quarterfinals while Ali Sher defeated Harendra Gupta 1-up in his quarterfinal encounter.

Semifinal line-up: Arjun Singh vs Lim Chih Bing; Shamim Khan vs Ali Sher.

Results (Quarterfinals):

Arjun Singh bt Ashok Kumar 1-up; Lam Chih Bing (Sing) bt Manav Jaini 6 & 5; Shamim Khan bt Naman Dawar 5 & 4; Ali Sher bt Harendra Gupta 1-up.