Head coach Warren Gatland was pleased with a Lions performance "out of the top drawer" against the Waratahs - but is concerned over the fitness of centre Jamie Roberts.
The Lions produced their best display of the tour so far as they ran in five tries to beat a punchy Waratahs side 47-17 in the penultimate match before the first Test against Australia next weekend.
Leigh Halfpenny scored 30 points alone - with two tries and eight successful kicks at goal - while Jonathan Sexton, Tom Croft and Jon Davies also touched down.
But there was concern for Roberts, who hobbled off late in the match with anxiety etched deep into his face.
Gatland said: "He's going to get a scan tomorrow. The medics thought it might have been a hamstring, but he said he has never pulled a hamstring before.
"He's not kind of sure, so he's got his fingers crossed that it may not be that. So we just have to see what happens tomorrow."
The Lions coach was far more upbeat about his side's display, saying: "They put it up to us physically. I thought the boys responded really well. That was a performance out of the top drawer.
"The last 12 minutes we were down to 14 men and they just kept plugging away and we dominated that period really well so I am proud of that performance.
"I thought defensively we were strong. They were playing a three-pod system and we spoke about that at halftime and had to fix up a few things.
"But we came off our line pretty well and I thought our contact was good, our rucking delivered some good front football for our backs and the set-piece again was excellent. The scrum was strong and the lineout was good as well. We showed a little bit tonight but not too much."
A number of players impressed and put their hands up for a starting berth in the first Test against the Wallabies, seven days from now.
And asked who had impressed him, Gatland said: "I thought Alun Wyn Jones. I thought his physicality and presence out there was outstanding. He carried, defended really well and I thought he was a real cog for us.
"Marko Vunipola again carried well and Jon Davies was good in the midfield so there were some really good performances. Also Halfpenny goalkicking and a great start for Simon Zebo too."