The visitors opened day four with a lead of 48 and with eight wickets in hand, and Croft hit an unbeaten 104 before the Red Rose declared on 322 for seven.
The 29-year-old then took centre stage in the Lancashire bowling attack, taking three wickets as Warwickshire lost five wickets in the final session.
But the Bears clung on to avoid defeat, with the captains shaking hands with the hosts 86 for five.
A draw was always the most likely outcome, but it was the hosts who had thoughts of winning early on when Andrea Agathangelou was stumped on 19 and Simon Kerrigan could only add six before being caught off the bowling of Jeetan Petal.
But Ashwell Prince and Croft steadied the ship, and set about creating a potential match-winning situation for their side.
Ambrose bowled by Kerrigan GAME ON!!!! http://t.co/VgdiIDaQwj
— Lancashire CCC (@LancsCCC) June 11, 2014
Prince made 36 before falling in the same fashion as Agathangelou but Croft was helped along by Jos Buttler, Tom Smith and Glen Chapple, who all added at least 20 each, with the declaration soon following Croft's seventh first-class century.
Warwickshire had around 40 overs to bat, with an unlikely 287 to win, but their innings turned into a survival bid as Croft put in a star turn with the ball.
Opening pair Varun Chopra and William Porterfield started well but their partnership fell two runs short of 50, when the latter was run out and Chopra became Croft's first victim shortly afterwards.
Laurie Evans and Sam Hain were also snared by Croft, the first caught by Paul Horton and the latter trapped lbw for a duck.
Tim Ambrose also failed as he could manage just one run before Kerrigan bowled the hosts' wicketkeeper.
But with a minor miracle required to force five more wickets in around 20 minutes of playing time, Ateeq Javid and Rikki Clarke dug in to ensure there would be no more drama, with Warwickshire emerging with 10 points to Lancashire's nine.