Richard Karlberg of Sweden tightened his grip in the SAIL Open after retaining his lead with a second-round three-under-par 69 yesterday. The Asian Tour rookie produced an impressive back-nine performance highlighted by four birdies for a two-day total of 10-under-par 134 at the Delhi Golf Club. Veteran Gaurav Ghei of India rolled back the years when he signed off with a 67 to sit in second place on 135 while compatriot Shamim Khan and Thai stalwart Chinnarat Phadungsil are a stroke back on 136 in the US$300,000 event.