Kylian Mbappe struck twice and created Eduardo Camavinga's goal for the win at San Mames.
Xabi said afterwards: "It was an important match. We wanted to break the pattern a bit, but we came in calm and well prepared, and I think the team performed very well overall. We were very focused for the full ninety minutes, conceding very little.
“In the first half, we played very well and created chances. It was probably the most well-rounded match we've played. At a demanding stadium and at an important moment. We're taking things slowly, now we have to keep going.”
On Mbappe's brace, Xabi also said: “He's in great form. He scored two more great goals today. His movement and link-up play with Vini Jr. was very good. The team came out focused from the first minute to win the game with intensity and good tempo.
"We dominated the match in the first half and in the second half, though we didn't have as much possession, we remained in control.
"It was an important moment after three away draws to get back to winning ways. On Sunday, we return home."