The Ospreys were nearly guilty of blowing another big lead, before Dan Biggar's penalty gave them a 25-24 win over Clermont on Sunday.
The Ospreys having led 22-3 at the break, three tries in 14 minutes put Clermont back in front at 24-22 at the start of the second half before Biggar's 64th-minute penalty clinched the win.
It's difficult to know why this happened. Were Clermont really that bad in the first half or were the Ospreys that good? Were Clermont that good in the second or the Ospreys that bad? You couldn't pinpoint reasons - both sides came and went from the game as they pleased, mixing sublime with substandard with teasing frequency. The game threatened to develop into a classic but never quite made it - an indication of both teams' performances. It was fitting that both nearly got a try bonus, but with 25 minutes left at the end neither could find the necessary oomph to get home.
It was also nearly a case of 'only the French'. Clermont really were poor in the first half, a yard off the pace at times and never hitting their tackles properly. People here were joking at the break - with a thinly-veiled reference to the Ospreys' capitulation at Leicester last week - that Clermont were so bad they'd be bound to score four tries and bounce back in the second half, simply becuse they were French. Once Alexandre Lapandry had scooped up a loose ball to cross over for the third after 54 minutes, one or two of those jokers looked ashen.
There was a scare for Wales less than three weeks before they take on New Zealand in the opening autumn international with Mike Phillips limping off with an injury to his right ankle.
Ospreys showed positive intent from the start and Dan Biggar scored a drop goal in the second minute.
And they went further ahead seven minutes later with a well worked try for centre Tommy Bowe, who latched onto Nikki Walker's neat chip ahead.
Clermont responded with a drop goal of their own from Australian outside-half Brock James but the visitors suffered a blow to their chances of getting back on terms when second row Thabault Privat was shown a yellow card for a trip on Shane Williams.
With the extra man Ospreys took full advantage as Ryan Jones went over for the second try from short range. Biggar converted to give the home side a 15-3 lead on 28 minutes.
But Ospreys were also reduced to 14 men with the sin-binning of Jerry Collins two minutes later for an illegal challenge on James.
A second setback for the Ospreys, and a worry for Wales, saw Phillips limp off on 33 minutes. He was replaced by Jamie Nutbrown.
But despite that the home side scored their third try with the last move of the first period. Barry Davies went over after a neat chip ahead from Biggar was collected by Bowe and passed through the hands.
If Ospreys had dominated the first half, Clermont certainly made an impact at the start of the second, scoring three converted tries to turn a 19-point deficit into a 24-22 lead.
The first try arrived within the first two minutes. After a couple of darts by scrum-half Kevin Seino, flanker Julien Bonnaire kicked ahead and with Ospreys defence nowhere to be seen, winger Benoit Baby scored.
Replacement prop Domingo squeezed over for the second try and made the break which saw flanker Alexandre Lapandry go over three minutes later.
Ospreys stopped the rot on 64 minutes with a well-struck long-range penalty by Biggar as they went back into the lead at 25-24, and Clermont then had a try disallowed when wing Napolini Nalaga was forced into touch before getting the ball down in the left corner.
Ospreys clung on for the win after James struck the left upright with a 74th-minute penalty.
For the Ospreys:
Tries: Bowe, R.Jones, Davies
Cons: Biggar 2
Drop goal: Hook
Tries: Baby, Domingo, Lapandry
Cons: James 3
Drop goal: James
Yellow cards: Privat (25, Clermont), Collins (29, Ospreys)
Ospreys: 15 Barry Davies, 14 Nikki Walker, 13 Tommy Bowe, 12 James Hook, 11 Shane Williams, 10 Dan Biggar, 9 Mike Phillips, 8 Ryan Jones (capt), 7 Marty Holah, 6 Jerry Collins, 5 Jonathan Thomas, 4 Alun-Wyn Jones, 3 Cai Griffiths, 2 Huw Bennett, 1 Duncan Jones.
Replacements: 16 Richard Hibbard, 17 Paul James, 18 Craig Mitchell, 19 Ian Gough, 20 Filo Tiatia, 21 Jamie Nutbrown, 22 Andrew Bishop, 23 Sonny Parker.
Clermont: 15 AurÃ©lien Rougerie, 14 BenoÃ®t Baby, 13 Gonzalo Canale, 12 SeremaÃ¯a Bai, 11 Napolini Vonowale Nalaga, 10 Brock James, 9 Kevin Senio, 8 Elvis Vermeulen, 7 Alexandre Lapandry, 6 Julien Bonnaire, 5 Thibaut Privat, 4 Jamie Cudmore, 3 Martin Scelzo, 2 Mario Ledesma, 1 Lionel Faure.
Replacements: 16 Willie Wepener, 17 Thomas Domingo, 18 Vincent Debaty, 19 Jason White, 20 Julien Bardy, 21 Morgan Parra, 22 Brent Russell, 23 Gavin Williams.
Referee: Wayne Barnes (England)
Assistant referees: Sean Davey(England), Peter Huckle (England)
Television match official: Geoff Warren (England)