Tom Kohler-Cadmore agonisingly missed a maiden first-class century as Division Two leaders Worcestershire moved into a strong position on the third day at New Road.
The 19-year-old was bowled by Dan Redfern for 99 after helping his side to a declaration at 416-8, which set Leicestershire a daunting target of 458.
Greg Smith opened up with eight fours in an unbeaten 38 but Angus Robson (8) and Ned Eckersley (3) were out to the seamers as Leicestershire reached 56-2 in 21 overs by the close. The team will require a further 402 runs on the last day.
Kohler-Cadmore shared in century stands with Alexei Kervezee (75) and Joe Leach (74) as the Pears escaped from a potentially vulnerable situation when overnight batsman Rich Oliver (37) played on to Leicestershire's leading wicket-taker Nathan Buck from the fifth ball of the day.
At 50-3 - all the wickets having fallen to the impressive Buck (17.1-3-80-3) to take his seasonal tally to 39 - the promotion contenders were only 91 ahead and a batsman short after preferring a bowler as deputy for England all-rounder Moeen Ali.
Another wicket when Kervezee, on 23, edged Rob Taylor (7-1-34-0) between wicket-keeper and first slip, with his side only 124 in front, could have opened the door to Leicestershire. Instead the game was wrenched away as 300 runs were scored in two sessions.
Kervezee initially led the counter-attack, seeing off the threat of Buck with three boundaries from four balls, and Kohler-Cadmore quickly imposed himself with his third half-century in five innings, a sequence which began at Grace Road last month.
Kohler-Cadmore’s front-foot driving caught the eye, and he also showed composure to see Worcestershire through a tricky spell against Charlie Shreck (18-4-70-2) after lunch. Kervezee mis-hit to Josh Cobb at mid-off after a stand of 131 and Ben Cox was trapped lbw.
Yet once more Leicestershire were pushed back as the big-hitting Leach raced to a 43-ball half-century and put on exactly 100 for the sixth wicket until Kohler-Cadmore was denied a career milestone after going to 99 with successive sixes off Redfern (9-2-44-1).
James Sykes (16-0-108-2) then dismissed Leach and Shaaiq Choudhry (25) in successive overs but there was more flak to come as Saeed Ajmal thrashed an unbeaten 53 - his fourth career half-century taking 42 balls - in an unbroken partnership of 80 in 9.4 overs either side of tea with Jack Shantry (30 not out).
Ben Smith, Leicestershire’s Senior Coach, said: “By the time Worcestershire had got a lead of 150 to 200 they could be a bit more aggressive. We were just trying to get some hold on the game. Unfortunately this just didn’t happen. Tom Kohler-Cadmore is a good player. I think he will be a fine player in the future.
“The challenge for us moving forward to tomorrow will be how well we play Saeed Ajaml. The team have got an opportunity to be proud of potentially getting a draw. If we do that, we will have to bat for a full day against the world’s best spin bowler and a seam attack that can back that up.”