diff --git a/packages/opentelemetry-sdk-trace-base/src/export/BatchSpanProcessorBase.ts b/packages/opentelemetry-sdk-trace-base/src/export/BatchSpanProcessorBase.ts
index f916e731a4..7cb7cb0b1d 100644
--- a/packages/opentelemetry-sdk-trace-base/src/export/BatchSpanProcessorBase.ts
+++ b/packages/opentelemetry-sdk-trace-base/src/export/BatchSpanProcessorBase.ts
@@ -150,13 +150,15 @@ export abstract class BatchSpanProcessorBase<T extends BufferConfig>
    * */
   private _flushAll(): Promise<void> {
     return new Promise((resolve, reject) => {
+      this._clearTimer();
       const promises = [];
       // calculate number of batches
       const count = Math.ceil(
         this._finishedSpans.length / this._maxExportBatchSize
       );
       for (let i = 0, j = count; i < j; i++) {
-        promises.push(this._flushOneBatch());
+        const spans = this._finishedSpans.splice(0, this._maxExportBatchSize);
+        promises.push(this._export(spans));
       }
       Promise.all(promises)
         .then(() => {
@@ -166,9 +168,8 @@ export abstract class BatchSpanProcessorBase<T extends BufferConfig>
     });
   }
 
-  private _flushOneBatch(): Promise<void> {
-    this._clearTimer();
-    if (this._finishedSpans.length === 0) {
+  private _export(spans: ReadableSpan[]): Promise<void> {
+    if (spans.length === 0) {
       return Promise.resolve();
     }
     return new Promise((resolve, reject) => {
@@ -178,11 +179,6 @@ export abstract class BatchSpanProcessorBase<T extends BufferConfig>
       }, this._exportTimeoutMillis);
       // prevent downstream exporter calls from generating spans
       context.with(suppressTracing(context.active()), () => {
-        // Reset the finished spans buffer here because the next invocations of the _flush method
-        // could pass the same finished spans to the exporter if the buffer is cleared
-        // outside the execution of this callback.
-        const spans = this._finishedSpans.splice(0, this._maxExportBatchSize);
-
         const doExport = () =>
           this._exporter.export(spans, result => {
             clearTimeout(timer);
@@ -232,12 +228,13 @@ export abstract class BatchSpanProcessorBase<T extends BufferConfig>
   }
 
   private _flushOneBatchAndContinue() {
-    this._flushOneBatch()
+    this._clearTimer();
+    const spans = this._finishedSpans.splice(0, this._maxExportBatchSize);
+    this._export(spans)
       .then(() => {
         if (this._finishedSpans.length >= this._maxExportBatchSize) {
           this._flushOneBatchAndContinue()
         } else if (this._finishedSpans.length > 0) {
-          this._clearTimer();
           this._maybeStartTimer();
         }
       })
@@ -246,7 +243,6 @@ export abstract class BatchSpanProcessorBase<T extends BufferConfig>
         if (this._finishedSpans.length >= this._maxExportBatchSize) {
           this._flushOneBatchAndContinue()
         } else if (this._finishedSpans.length > 0) {
-          this._clearTimer();
           this._maybeStartTimer();
         }
       });