With over 80 per cent of votes being counted, the UDF is seen as winning in 19 seats, with the ruling CPI-M set to win just the Alappuzha seat.
Speaking to the media at his residence here, as hundreds of UDF workers came to greet him for the expected win, Chandy said he wished to thank the people of Kerala who made it possible.
"We have been saying it would be 20-20 this time for us. Though we are trailing in Alappuzha, I still feel, we will surge ahead there also and make a clean sweep. This win happened because all sections of Kerala society voted for us," said Chandy.
"This is a verdict against the Kerala government. The presence of Rahul Gandhi at Wayanad also helped us in a big way," added Chandy.
While the BJP was expecting to perform well and at least win one seat, if not two, things at the moment do not look good for the saffron party as in Thiruvananthapuram, sitting Congress member Shashi Tharoor is ahead by over 45,000 votes, with BJP's Kummanem Rajasekheran in second place.
Likewise at Pathanamthitta, where the Sabarimala temple is located, BJP candidate K. Surendran slipped to the third position after leading for a while.
( With inputs from IANS )