Till 6.30pm, 80.92 per cent votes were polled in the Maoist-affected constituencies of Jungle Mahal - around 3.5 percentage points less than the 2014 Lok Sabha poll turnout of 84.46 per cent.
The 3.5 per cent drop may look small but, if represented in absolute numbers for an average Assembly segment, it would mean 7,000 votes, a reasonable victory margin in any seat.
Conventionally, a low voter turnout is considered favourable for the ruling party while a high number is linked to anti-incumbency but the Opposition claimed that Bengal, with its history of "scientific rigging", was an outlier where the drop in polling was a welcome development.
"In Bengal, the dip indicates that anti-incumbency is kicking in. Besides, the Election Commission of India also needs to be congratulated for cleaning up the electoral rolls and preventing bogus voters from casting votes," said Sidharth Nath Singh, BJP national secretary and minder for Bengal.
The last few elections - to panchayats in 2013, Lok Sabha the following year and civic bodies last year - had seen a high turnout, which the Opposition parties attributed to Trinamul rigging by loading electoral rolls with ghost voters. There were also complaints that a lack of vigil by the poll authorities had enabled the ruling party cadre to cast false votes.
All the Opposition parties had urged the EC to clean up the rolls and keep a hawk eye on booths to ensure that the ruling party did not cast votes for absent, shifted and dead voters.
Biswanath Chakraborty, professor of political science at Rabindra Bharati University, said: "Though the rolls are yet to be cent per cent clean, the commission has managed to ensure bulk removal of such names."
Proof of the clean-up lay in reduced turnout compared to 2014 in several constituencies like Nayagram which recorded 80.72 per cent (85.96), Gopiballabhvpur 85.49 per cent (89.44), Salboni 86.61 per cent (92.97) and Midnapore 78.77 per cent (88.01).
Another political scientist said the lower turnout would likely reduce Trinamul's vote share, bringing the Left-Congress alliance closer to the ruling party. "If the alliance can get a share of the BJP's votes, likely to decline this time, the contest becomes too close," he said.
Although the mood in the Opposition camp was bullish, Trinamul sources said they were confident of winning a significant majority in the 18 seats spread across the three districts of Purulia, Bankura and West Midnapore.
Party vice-president Mukul Roy did not want to get into the question of a dip in polling percentage and its likely impact. "We are happy that there was a good turnout and people could cast their votes peacefully," he said.
Deployment of central forces at booths - visible in most places - played a key role in ensuring peace and reducing malpractice.
"The number of booths (out of 4,945) where the Trinamul had a free run would be around 50-60 (barely one per cent). In 2014, the number of such booths was well over a thousand (20 per cent)," said a CPM state secretariat member.
He attributed the improvement to two main reasons: tighter vigil by the poll panel and a competitive political environment outside booths. The Opposition parties have, however, asked the poll panel to draw lessons from Monday's experience and pull up its socks in the next phases.
The areas where the polls were held on Monday had become Trinamul strongholds since 2007, when there was an attack on then chief minister Buddhadeb Bhattacharjee while he was returning after inaugurating the Jindal steel project in Salboni.
"Because of the alliance between the Congress and the Left, there was a competitive political environment outside booths, which prevented the ruling party from calling the shots, something they have been doing in the past few elections," explained Chakraborty.
The Left, Congress and BJP mentioned only a "few" incidents of malpractice. The violations ranged from entry of state police personnel inside booths and booth-capturing in a few places. There was an assault on the Left candidate and the media in Salboni and an attack on BJP polling agents.
"I cannot say that the polling was completely free, fair and peaceful. But it was better than the last few elections," said Mohammad Salim, CPM politburo member and Lok Sabha MP.
Sources in Nirvachan Sadan said the commission would analyse the minutiae of the polling process to assess the need, if any, to alter arrangements for the remaining phases.