(CNN)It was a straightforward header from close range that put Borussia Dortmund 3-1 ahead in the second half of its league game Saturday, but the simplicity of the goal should not mask its significance.
Sébastien Haller's goal was his first since returning to play three weeks ago, having needed to take time off from the sport to undergo treatment for testicular cancer.
He happened to score on International World Cancer Day, an occasion the German club marked by putting a 'tumor' on the center circle before the match and at halftime to raise awareness of testicular cancer.
The 28-year-old was diagnosed days after signing for Dortmund last summer and has needed two operations and four rounds of chemotherapy.
"I've been waiting for this moment since day one. When I scored the goal, it felt like the whole stadium was on fire," Haller told Sky Sports. "I am happy, but the way is still long, so we will keep walking and hope for more goals."
Haller played his first league game for Dortmund on January 22 and made his first start for the German side a week later.
The Ivory Coast international scored 47 goals in 66 games for his former club Ajax during an 18-month spell, 11 of which came in the Champions League.
He signed for Dortmund on July 6 but began to feel unwell during a preseason training camp in Switzerland later that month.
Dortmund's sporting director Sebastian Kehl told Sky Sports: "We were all happy for Sébastien. He's been working towards this day for a long time, it's a big weight off his shoulders, we're all excited and overjoyed.
"He's capable of playing even better when he discovers his old rhythm. But the goal will help with that, of course."
Dortmund went on to beat 10-man Freiburg 5-1 to make it four wins from four league games. The win moved Dortmund to third in the Bundesliga, two points off leaders Union Berlin.
Freiburg had Kiliann Sildillia sent off in the 17th minute for two bookable offenses within three minutes of each other.