The 25-year-old Scot overcame Tomas Berdych 5-7 6-2 6-1 7-6 (9/7) at Flushing Meadows on Saturday to advance his fifth major final, where he will face either Novak Djokovic or David Ferrer.
And Lendl, who has been working with Murray since January, reckons the Olympic champion has never been better equipped for grand slam success.
He said in the Sunday Mirror: "Andy is ready to go and win. The lesson he learned from the Wimbledon final was a tough one but he learned it well and put it to good use in the Olympic final.
"Andy and I are very similar in that we lost four slams in a row. If you look at his losses, he has been beaten by Roger Federer three times and Novak Djokovic.
"I lost to Bjorn Borg and I lost to Jimmy Connors twice. With Mats Wilander on grass in Australia I didn't really know how to play and I was not in my prime and still learning. Andy is now in his prime.
"After Wimbledon I said to him, 'You should be proud of yourself for the way you handled the pressure and the way you played'.
"There was a big difference between this loss and the one he had to Djokovic in Australia the previous year.
"You learn from certain losses and become depressed from other ones. But when you put it all out there and go hard, you can be proud of yourself. And you can learn from it, and that is really important."