US star Spieth is the man to beat, but Kuchar is on his tail

such has been his form all week that it will take a Herculean effort from one of the chasing pack to close the gap on him.

In the nine previous Open Championships here in Southport, the halfway leader has gone on to lift the Claret Jug just once.

That was Lee Trevino, way back in 1971.

But who would bet against his fellow Texan emulating old Supermex.

Kuchar would have been even closer to Spieth had he not double-bogeyed the 16th to drop three shots back.

And, even though he recovered with a birdie at 17, Spieth held his nerve in front of the clubhouse for birdie on 18 to put himself in a solid lead. Spieth said: “Being a very favourable day for scoring and recognising that ahead of time made it pretty tough mentally. “It was a day where you had to play aggressive. The shot on three was big for me to get started. “And the par saves around eight or nine were the most stress I had all day. I’m extremely pleased and I couldn’t ask for much more. “It was important to stay ahead of Kuch, but I didn’t think it was extremely important. “Our game plan when we stood on the tee was to push ourselves and get this pairing for tomorrow. “I wanted to get to 10 under and nothing changed. I stayed out of trouble off the tee and, after the first two holes, it was my best performance I’ve had in my last few events.” Young Canadian Austin Connelly, playing in his first Open, is tied on third, with Brooks Koepka, six shots behind Spieth. Grace and Hideki Matsuyama are tied a further shot back. But they will all have to go on some charge to catch two-time Major winner Spieth.