Defending champion David Ferrer signaled his intent at the Valencia Open with a straight-sets victory over Gael Monfils on Wednesday.
The number-one seeded Spaniard, born in Valencia, was in dominant mood at the ATP 500 hard-court indoor tournament, claiming a 6-3, 6-2 success against his unpredictable French opponent.
The first set hinged on three breaks in as many games, with Ferrer emerging from that spell 4-2 ahead before claiming the lead.
He stepped it up another gear in the second set to take two breaks and book his place in the next round as he eyes a fourth title in his hometown.
Fabio Fognini and Dmitry Tursunovearned spots in the last eight with convincing wins.
Marcel Granollers fell victim to the Italian, losing 6-3, 6-2. Tursunov overcame Roberto Bautista Agut 6-2, 7-6 (7-3).
Fourth seed John Isner produced the goods when it mattered as he saw off the challenge of Latvia's Ernests Gulbis, prevailing 7-6 (7-4), 7-6 (7-2) in their first-round meeting.
The American failed to capitalise on the six break-point opportunities he carved out in the opening set but, after trailing 3-1 in the tie-break, fought back to claim the advantage.
He had to survive a few threats to his own serve in the second, holding his nerve in the face of seven break-point openings for Gulbis at 2-2.
Again it came down to a breaker and this time Isner was even more convincing, dropping just two points.
The biggest shock of the first round saw Philipp Kohlschreiber come from a set down to defeat second seed Tommy Haas 3-6, 6-3, 6-3.
Kohlschreiber recovered from a low-key start to end the challenge of his fellow German at the first hurdle.
Frenchman Jeremy Chardy was taken the distance by Florian Mayer before eventually triumphing 4-6, 7-5, 6-3.
Having claimed the first set, Germany's Mayer was broken at 5-6 in the second and one break early in the third proved enough for Chardy to complete the comeback.
Also in round one, Jarkko Nieminen beat Benoit Paire 6-3, 6-3.