The man, a resident of Vishwas Nagar in Shahdara, works as a taxi driver.
He had plans to elope with the woman, who happens to be the wife of his brother-in-law today, they said.
However, the woman refused to go with him.
Agitated over the refusal, he returned home and poured kerosene on his body and set himself on fire, police said.
His wife tried to save him but also ended up sustaining injuries.
The man, who sustained 35 per cent burns, is currently undergoing treatment at GTB Hospital, police said.
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