The Sunwolves put in a much-improved performance on Saturday but it still wasn't enough against the Southern Kings of South Africa, with the visitors winning 37-23 in Singapore.

Japan's Super Rugby franchise made it clear they would not let the demolition they suffered in the season opener define their year, showing the resilience and fight that was missing for large parts of last week's match, when they were defeated 83-17 by the Hurricanes.

The Kings scored four tries to the Sunwolves' three, but it was the kicking and general dominant play of the Kings' No. 10 Lionel Cronje that made the difference, with the physical playmaker perfect on both conversions (four) and penalties (three).

"(Our) execution of skills, I believe (let us down)," said Sunwolves captain Ed Quirk. "We had good opportunities inside the 22, and kicked the ball away, we'll have a look at that.

"You saw last week that our last 20 minutes is always our good 20 minutes. We've got to try to transfer that into the start of the game," he said.

After a competitive first half in which the Sunwolves had the better of the run of play, the Japanese team looked poised for a strong back end, but a lack of discipline on defense cost them as the teams traded penalties, not allowing the home team to cut the deficit.

"Obviously, we piggybacked them all the way down (the second half) with stupid penalties," said Quirk. "All credit to the Kings, they definitely capitalized on everything."

Sunwolves head coach Filo Tiatia echoed his captain's words.

"They capitalized on their opportunities and we weren't clinical enough and didn't hold onto the ball," he said. "We also made some poor decisions."

"When we did get our roles right we put the Kings under pressure but we need to do that consistently."

Deon Davids, head coach of the Kings, was proud of his squad's ability to overcome a terrible injury toll that saw him go deep into his bench.

"To lose our main line-out jumper and then both scrumhalves, it was a really tough win and I applaud the effort of the boys in taking on the challenge," he said.

"The Sunwolves had us scrambled on defense and if they had more continuity they could have converted that into points."

The Sunwolves had the better of play early in the first half, dominating both possession and territory, but it was the Kings who crossed first.

Kings' speedster Malcolm Jaer was the beneficiary of some sloppy Sunwolves play at the breakdown, picking up a ball that popped out of the ruck, going 60 meters the other way before putting Rudi van Rooyen in under the posts.

Tokyo's team did not let that setback change the momentum, however, and just five minutes later Derek Carpenter had a certain try in front of him after new No. 10 Hayden Cripps put him in space, but the Kiwi-born center got ahead of himself and spilled the ball.

The Sunwolves' Singaporean faithful did not have to wait much longer for a payoff, though, when experienced halfback Fumiaki Tanaka — perhaps the Sunwolves best player on the day — took a quick tap 10 meters out and spun the ball wide to Timothy Lafaele who took two defenders over the line with him for the Sunwolves first try.

Seven minutes before halftime the Kings extended the lead further when Jaer again broke through. He was pulled down short of the line, but reserve back-row forward Chris Cloete was there to clean up, cross and make the score 17-7 at the break.

Defense dominated for large parts of the second half, with both teams unable to penetrate the line.

The teams traded penalties up to 23-13 before the Kings strung together a strong driving maul, rumbling forward more than 20 meters before Ruan Lerm reached across the line to stretch the lead to 30-13 after the conversion.

Kenki Fukuoka kept the Sunwolves within shouting distance when he snagged an intercept and sprinted to the corner, but just seconds later Jaer returned the favor with a moment of individual brilliance to go over wide.

Jamie-Jerry Taulagi, who had an extremely impressive Sunwolves debut after coming on in the 51st minute, gave the local crowd a moment to remember after the horn when he threw a special pass behind his head, finding Takaaki Nakazuru for the game's final score.

With the Sunwolves back on the road for their next two matches before they return to Singapore for round five, Quirk knows the team has a rough road ahead.

"We need to repay our fans," he said. "I know we have a tough week coming up. But for us, we are going to stay on the grind and keep getting better."