In 1982, Lai issued the first written decision on the granting of a Mareva injunction in Singapore in the Art Trend Ltd v Blue Dolphin (Pte) Ltd case.

[3] In October 1984, Lai presided the manslaughter trial of Beh Meng Chai, a Malaysian and one of the three perpetrators of the 1980 Jurong fishing port murders, in which a fisher dealer Lee Cheng Tiong and a teenager Teo Keng Siang were both robbed and killed.

[7][8] In 1986, Lai sentenced Malaysian businessman and the then-MCA President Tan Koon Swan to a S$500,000 fine and two years' imprisonment in Singapore, for Criminal Breach of Trust (CBT) which led to the collapse of Singaporean company Pan-Electric Industries.

[9] In his judgement, Lai said Tan's offences had "struck at the very heart, integrity, reputation and confidence of Singapore as a commercial city and financial centre".

[11][12][13] Lai was also one of the two judges (the other being Joseph Grimberg) who sentenced Sim Ah Cheoh, a housewife and single mother of two sons, and her two bosses - Lim Joo Yin and Ronald Tan Chong Ngee - to death in 1988 for attempting to illegally import 1.37 kg of heroin from Singapore to the USA.

Much of the deposits were deemed to be kickbacks from corruption practices by the General Thahir, during his office in Pertamina between 14 October 1968 and the day of his death on 23 July 1976.

[18] The judgement passed by him deeply impressed The Privy Council in Britain, and formally accepted Lai's rejection of exercising an English legal authority on the Commonwealth corruption law that had been upheld for more than a century.

[19] In March 1993, Lai also presided the trial of Yap Biew Hian, a Malaysian shipyard worker charged with killing one of the female tenants of his rented house at Katong there years before.

[28] On 24 June 1995, Lai found mechanic Nadasan Chandra Secharan guilty of murdering his lover Ramapiram Kannickaisparry and sentenced him to death.

[29][30][31] On 12 May 2005, Singapore saw for the first time, a case involving exercise rights of discretion in the amendment of patent specifications for commercial products in the Trek Technology (Singapore) Pte Ltd v. FE Global Electronics PTE Ltd and others, and other suits [2005] (SGHC 90)[32] Lai ruled on all counts, in favour of Trek 2000 International that their USB portable mass storage device patent to be valid, enforceable and infringed by Israel's M-Systems Flash Disk Pioneers Ltd, and Hong Kong's Ritronics Components.

Lai's last major case heard was that of the sexual assault cum murder of 8-year-old Chinese national Huang Na on 26 August 2005, by the accused Took Leng How.

He ruled all forensic evidence pointed to Took's guilt and to his admission of sexual assault and murder of Huang Na, as well as dismissing Took's defence that he was schizophrenic.