Monty completes thrilling comeback

Howell took the lead with four successive birdies from the 10th hole, but Montgomerie dug deep to birdie three of the next four holes and score a hard-fought one-up victory at Dove Mountain.

"That's a good effort," said Montgomerie, who joked that he would give himself a pat on the back if only he was a little younger and more flexible.

"We're in the last 16 and delighted. I look forward to playing again."

By pure co-incidence, Montgomerie, who beat Jim Furyk on Wednesday, has come up against Americans in the first two rounds.

European Ryder Cup captain Nick Faldo, in Tucson as a television commentator, must have been suitably impressed, and will have another chance to watch a mini Ryder Cup showdown on Friday as Montgomerie takes on yet another American, Stewart Cink.

In an all-British showdown, Englishman Paul Casey recovered from a slow start to mow down Welshman Bradley Dredge two and one.

It was turning into a mixed day for the European contingent, with Irishman Padraig Harrington and Spaniard Sergio Garcia making early exits.

Cink beat Harrington two-up, while Garcia was no match for Boo Weekley, the American winning decisively three and one.

Australian Aaron Baddeley advanced to the last 16 without even hitting a shot after his American opponent, David Toms, withdrew with a back injury.