San Francisco Frontiers - Defending champion Shelton rolls into Montreal semis

World number 10 Shelton, the last top-10 player in the field, was never challenged by the Czech in advancing to a Wednesday semi-final against either fellow American Learner Tien or Spain's Daniel Merida.

"It was a great performance for me, super happy with that and to be in the semis again," Shelton said.

Spanish teen Rafael Jodar booked a semi-final spot in only his fifth ATP Masters 1000 event by holding off France's Arthur Fils 7-6 (7/5), 6-3.

The 19-year-old will face the oldest remaining player when he plays 25-year-old American Brandon Nakashima in a Wednesday battle for a place in Thursday's final.

Nakashima reached his breakthrough Masters semi in 77 minutes as he imposed his game on Luciano Darderi 6-2, 6-3, setting up three match points with his 11th ace as winning as the Italian missed on a drop shot.

Shelton was on fire in his 72-minute thrashing of Mensik, the American producing 18 winners and only three unforced errors.

Shelton stands 12-2 in Canada and has yet to lose a set at this edition.

"I felt great, I played well form the ground from point one," Shelton said. "I'm right where I want to be.

"I maintained a high level throughout the match. I'm super happy with how I played. I hope to continue to build on this in the semis."

Jodar shrugged off a slight tweak of his ankle in the second set against Fils and remained calm throughout as his French opponent smashed a racquet after being broken early in the second set.

Jodar, who does not turn 20 until after the US Open ends next month, has won 34 matches this season and risen to 15th in world rankings, but seeing improving his game as more important than his ranking.

"That shouldn't be your primary thing and your goal," he said. "My goal is to have fun on court and to enjoy all the tournaments that are new for me."

Fils, back after injury, saved three match points in the final game before Jodar lanced a winner to the empty court after an hour and three-quarters in a match interrupted for an hour by rain.

"I played a very high level today against a tough player like Arthur," Jodar said. "I had to give my best to win this match."

Nakashima, who won his fifth quarter-final of the season, credited his serve with the win.

"My serve was super important. It got me out of some tough holes," Nakashima said.

"I also took my opportunities on return when I needed to. I knew I had to open up the court. He was hitting his spots really well."

Nakashima, into his 16th career semi-finals, put his confidence "at an all-time high" after his seventh victory in eight matches following a Washington semi-final run.

K.Torres--SFF