Warren Gatland said watching his Wales team withstand a second half Samoan onslaught was too close for comfort, but he is happy to come away from Cardiff with the win.
Wales registered their first win of the Invesco Perpetual Series 09 by edging Samoa 17-13 in front of 58,907 fans on Family Night.
And the huge crowd went home happy, but had to endure a nervy final 20 minutes after Wales failed to turn their dominance into points.
Coach Gatland explained afterwards, "We wanted to be more ruthless in our approach, but unfortunately we weren't. We created a lot of chances and line breaks and e should have put the game away.
"But we simply weren't clinical enough. We have to learn from our mistakes and in the first-half we kept kicking the ball away.
"We felt physically that if we kept playing with tempo their forwards would struggle and tire later on.
And the Kiwi coach would have been as nervous as anyone as Samoa pulled to within a converted try over a monumental win after Mapusua scored an interception try on the hour mark.
Gatland said; "It was a little bit too close for comfort in the end and we put ourselves under pressure. We made 11 line breaks to their two and our finishing wasn't good enough.
"We should have put the game away comfortably. The game should have been out of sight by the time they got their interception try - that was a 14 point try because if he hadn't have caught it we would probably have scored.
"But we have come away with a win."
Captain, and Man of the Match Ryan Jones commented: "It was about as tough as it gets in Test match rugby. The Samoans gave everything and really hit hard.
"But our boys dug deep for the victory that we wanted and needed. There is a courage, strong work rate and work ethic with my guys and it was great we kept them out in the last five or six minutes.
"We need to look at cutting out the mistakes. We have been offering so much, but not quite delivering - we haven't had that clinical edge in our game.
"It has been a case of the last pass or the last phase letting us down.
"But fair play to the Samoans, they came together on Sunday and put a fantastic performance together.
"The game against Argentina is going to be very difficult and we have got to take more ownership of the game and cut down on the errors.
Wales U20 duo Leon Brown and Lloyd Lewis face a busy couple of weeks ahead. Not only will they have a Junior World Championship to take part in, they are both sitting A Level exams during the competition.
Wales U20 face a tough group in the Junior World Championship with France, England and Japan lying in wait but Attack coach Jason Strange and back rower Tom Phillips are looking forward to the campaign ahead.
Angus O'Brien has quickly settled into the Wales Sevens squad after solid performances in Hong Kong and Japan. With two rounds remaining in Glasgow and Twickenham on the World Series, WRU TV's Graeme Gillespie chats to the rising star.
Wales winger Luke Morgan has established himself as one of the deadliest finishers on the Sevens World Series. WRU TV's Graeme Gillespie catches up with him on the eve of this weekend's round in Glasgow.
All roads lead to Cardiff on Sunday for the SSE SWALEC Finals Day at the Millennium Stadium. Cambrian Welfare tackle Ystradgynlais in the Bowl final, Ystrad Rhondda play Newcastle Emlyn in the Plate final while defending champions Pontypridd face Bridgend in the Cup final.
WRU Chief Executive Roger Lewis, Deputy Minister for Culture, Sport and Tourism Ken Skates and WRU Chairman Gareth Davies earlier this week launched a new competition in conjunction with the WRU unveiling its archive room.
Welsh players and management joined Deputy Minister for Sport Ken Skates at the Pierhead Building, Cardiff Bay earlier this week to reveal the Union's pioneering school-club hub initiative has been so successful the project will now almost double the scale of the original project.
The Scarlets, Newport Gwent Dragons, Cardiff Blues and the Ospreys look ahead to Judgement Day III which sees the Blues take on the Ospreys (2.30) and the Dragons tackle the Scarlets (4.45pm) at the Millennium Stadium tomorrow afternoon.
Ystradgynlais and Ynysddu played out a titanic struggle at Taffs Well in the SSE SWALEC Bowl semi-final. At the end of the game neither team could be separated after a 15-15 stalemate but Ystradgynlais go through on try count.