The anti-EU party gained three second-place finishes in the elections counted at the Guildhall today and were only once knocked into last place.
They stood in 11 of the 19 contests and although they did not directly affect any result they raked in more than 3,100 votes.
The Tories had been on the verge of taking overall control, with the crucial 29th seat, but their candidate in The Alresfords, Lisa Griffiths, was just unable to oust Margot Power, falling short by 79 votes.
UKIP had a respectable showing, finishing second in three wards and last only once. They polled more than 600 votes in Denmead.
Labour now has three councillors, their highest since 2004, with Clive Gosling winning in St John and All Saints ward that covers the Highcliffe and Winnall estates.
Conservative leader Rob Humby, who has replaced the retiring Keith Wood, said: “I'm delighted. The whole team have worked hard. We are now the largest group on the council.”
It was fifth time lucky for Helen Osborne, a mother of one in her 30s, who won the St Barnabas seat from the Lib Dems after a recount. She said: “It's so nice to be finally here.”
Labour leader Chris Pines said: “We are delighted, but not surprised as we were quietly confident. Our team hit every house in the St Johns ward.”
Kelsie Learney, Lib Dem leader, put a bright gloss on the results, saying her party had polled more votes across the district as a whole. “The Tories are still in overall control so we have still got influence,” she said.
Chris Barton-Briddon, secretary of the Winchester branch of UKIP, said: “We have done pretty well. It is down to continuous work by a few people but our numbers are growing.”
Turnout was boosted by coinciding with the Euro elections and twice topped 50 per cent, in The Alresfords, St Barnabas and Oliver's Battery and Badger Farm.
In a byelection at Alresford Town Council former city councillor Annie Saunders beat Steve Deeming and former town council chairman Robin Atkins.