Brown claims Isner scalp

Defending champion John Isner suffered a shock second-round exit at the Fayez Sarofim and Co Championship after losing to German Dustin Brown.

Brown, 101 in the ATP rankings, had never before beaten one of the world's top 10 players but he ended that run with a 6-4 6-7 (7/9) 7-6 (7/4) triumph over ninth-ranked Isner in a match that lasted two hours and 19 minutes.

The 29-year-old Brown said on "I got a little tight but you can't practise those things. That's just repetition of being in these situations, in matches against these guys. I'm really happy that this time I won it."

Next up for Brown in Houston is a quarter-final clash with another American in Sam Querrey, who knocked out another former champion and seventh seed Lleyton Hewitt 6-3 6-4.

Hewitt's fellow Australian Matt Ebden was also ousted, losing 6-1 6-2 to Santiago Giraldo.

Sixth seed Juan Monaco beat Somedev Devvarman 7-6 (7/4) 6-2.