Lancashire's clash with Somerset at Old Trafford in the Specsavers County Championship Division One was set for a fascinating finish.
At lunch Somerset required 266 runs to win with all their wickets in hand after another thrilling session
The hosts began this fourth and final day with a lead of 254 runs and had extended that to 295 by the time Lewis Gregory had dismissed Ryan McLaren (45) and Steven Parry (44) with Tim Groenewald accounting for Kyle Jarvis third ball for nought.
A short break for rain saw five overs lost from the day's play but with 77 overs to reach their target, Somerset faced the new ball pair of Jimmy Anderson and Jarvis with some confidence.
Trescothick was dropped behind the stumps on six by a diving Alex Davies off Jarvis but Lancashire went into the interval knowing they cannot afford any more mistakes after lunch with Somerset resuming on 29-0 off 10 overs.