Martin Vassallo Arguello defeated Igor Andreev 2-6 7-6 6-2 in the Monte Carlo Masters round of 64 on clay. The upset overturned the form book — Igor Andreev came in leading the head-to-head 1–0, defending last year's quarter-final. Martin Vassallo Arguello claimed a first win over Igor Andreev in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-05-25 | Roland Garros | R64 | clay | Igor Andreev | 1-6 7-5 5-7 6-3 6-4 |
Averages from each player's recent completed matches (20 vs 20). ATP, WTA & Challenger.