Surrey suffered a remarkable final day collapse to start the season with a 10-wicket defeat at the hands of Glamorgan at the Kia Oval.
Starting day four in command on 50-2 with a lead of 121, Surrey contrived to lose their last eight second innings wickets for just 33 further runs to leave Glamorgan chasing 152 to win.
The target proved no issue for the Welshmen, who knocked it off on the stroke of tea thanks to unbeaten half-centuries from Gareth Rees (75 not out) and Will Bragg (72no).
While Rees and Bragg confidently pulled off the run-chase, it was the bowling heroics of Graham Wagg and Michael Hogan which ultimately paved the way for an incredible Glamorgan fightback.
Left-arm seamer Wagg (6-29) followed up the dismissals of Surrey openers Rory Burns and Graeme Smith the previous evening with four further scalps to claim career-best figures, while Hogan proved the perfect foil, finishing with 4-31.
Glamorgan head back to Wales with 20 points, while pre-season favourites Surrey gathered just five.
At the Ageas Bowl, Hampshire and Worcestershire played out a draw - an outcome which had always looked likely due to rain disruptions over previous days.
Worcestershire captain Daryl Mitchell struck a majestic unbeaten 172 to help his side pick up four batting points from their first-innings 350-7 declared.
Mitchell shared a 154-run partnership with Moeen Ali, who picked up where he left off last season with a fluent 69 before falling to fellow left-arm tweaker Liam Dawson (2-67)
Ali then picked up the wicket of Michael Carberry (10) as Hampshire made 27-1 in their second knock before the players shook hands midway through the evening session on day four.