Agnieszka Radwanska happy with "tough" Jelena Jankovic victory

Agnieszka Radwanska has revealed that she was relieved to come through her "tough" contest with Jelena Jankovic in the third round of the US Open on Saturday.

The Polish second seed saw off her Serbian opponent 6-3 7-5 to set up a last-16 tie with Roberta Vinci.

"It's always tough and tight when we play, but I prepared well and I am happy to come through in straight sets," she said after the match.

Radwanska has equalled her previous best at the tournament by reaching the fourth round.