Jim Allenby hit an unbeaten 67 to steer Glamorgan to a thrilling three-wicket victory over Northamptonshire late on the fourth day at Wantage Road.
The former Leicestershire all-rounder hit the winning runs off the first delivery of the final over of a run chase that had been set up when the two captains agreed to forfeit an innings apiece.
After day three had been washed out Northamptonshire added 14 runs to their total of 336-5 before declaring, David Sales finishing unbeaten on 138.
Glamorgan's pursuit of 351 got off to a disastrous start when they lost opener William Bragg for a first-ball duck, however Gareth Rees (32) and Steven Walters (29) made useful contributions to their cause.
Marcus North top-scored with 73, adding 81 for the fourth wicket with Ben Wright (34), but when the Australian fell to seamer David Willey, the Welsh county looked in danger of falling short at 192-5.
Yet Allenby and Mark Wallace combined in a crucial partnership of 114 and although the latter was dismissed for 54 with the finishing line in sight, the visitors managed to squeeze home just before the close.
Northamptonshire's hopes of building a big score were thwarted as the third day of their match against Glamorgan was washed out without a ball being bowled.
Rain began to fall just as play was due to get under way and there was no respite, meaning umpires Mark Benson and Nick Cook had no option but to abandon the day at 1.15pm.
David Sales was denied the chance to build on the unbeaten 129 from 277 balls he piled on during the second day to help his team to 336-5.
Weather permitting, James Middlebrook will resume on 17 at the other end of the crease on the final day, with a result now extremely unlikely after the 15th full day that Glamorgan have lost to rain this season.
Rob Newton and David Sales both hit centuries as Northamptonshire's batsmen dominated the second day of their LV= County Championship match against Glamorgan at Wantage Road.
After being made to bat, the hosts closed on 336 for five with Newton smashing a career-best 117 off only 113 balls - his sensational knock including 14 fours and three sixes.
Sales finished unbeaten on 129 off 277 deliveries with 16 fours and he will resume on Monday with James Middlebrook, who made 17 not out from the last nine overs.
After the first day was washed out without a ball being bowled, Glamorgan won the toss and chose to field as the second day began on time.
The visitors' decision looked to have paid-off when they took the wicket of Stephen Peters with the final ball of the first over when he edged James Harris to Jim Allenby at second slip after facing six deliveries without scoring.
John Glover was brought into the attack in the 12th over and with his second ball he took out Kyle Coetzer's leg stump after the Scotland international had made 22. Glover then captured Alex Wakely for 30, caught by Stewart Walters at first slip.
Sales and Newton then dominated before Newton eventually holed out when he hammered Will Bragg to substitute fielder Aneurin Norman at deep mid-wicket to end a magnificent stand of 187.
Northamptonshire skipper Andrew Hall made just eight before he nudged Huw Waters to his opposite number - Glamorgan wicketkeeper Mark Wallace.
A sodden outfield meant the first day of the LV= County Championship match between Northamptonshire and Glamorgan was abandoned without a ball being bowled.
Torrential rain during Northants' Clydesdale Bank 40 match against Derbyshire on Friday evening had produced large pools of standing water around the Wantage Road outfield.
Further rain overnight ensured that conditions were unplayable, with umpires Mark Benson and Nick Cook calling off proceedings at 10:50am - over an hour before play was due to start.
Both teams will hope for conditions to finally improve on Sunday, with Northants looking to maintain a promotion push and Glamorgan striving to lift themselves off the bottom of the table.